diff --git a/src/main/java/picocli/AutoComplete.java b/src/main/java/picocli/AutoComplete.java
index 5e8fa650f..60d288630 100644
--- a/src/main/java/picocli/AutoComplete.java
+++ b/src/main/java/picocli/AutoComplete.java
@@ -715,16 +715,16 @@ private static String generateFunctionForCommand(String functionName, String com
 
     private static void generatePositionParamCompletionCandidates(StringBuilder buff, PositionalParamSpec f) {
         String paramName = bashify(f.paramLabel());
-        buff.append(format("  local %s_pos_param_args=\"%s\" # %d-%d values\n",
+        buff.append(format("  local %s_pos_param_args=(\"%s\") # %d-%d values\n",
                 paramName,
-                concat(" ", extract(f.completionCandidates())).trim(),
+                concat("\" \"", extract(f.completionCandidates())).trim(),
                 f.index().min(), f.index().max()));
     }
 
     private static void generateCompletionCandidates(StringBuilder buff, OptionSpec f) {
-        buff.append(format("  local %s_option_args=\"%s\" # %s values\n",
+        buff.append(format("  local %s_option_args=(\"%s\") # %s values\n",
                 bashify(f.paramLabel()),
-                concat(" ", extract(f.completionCandidates())).trim(),
+                concat("\" \"", extract(f.completionCandidates())).trim(),
                 f.longestName()));
     }
     private static List<String> extract(Iterable<String> generator) {
@@ -749,7 +749,9 @@ private static String generatePositionalParamsCases(List<PositionalParamSpec> po
             int max = param.index().max();
             if (param.completionCandidates() != null) {
                 buff.append(format("%s    %s (( currIndex >= %d && currIndex <= %d )); then\n", indent, ifOrElif, min, max));
-                buff.append(format("%s      positionals=$( compgen -W \"$%s_pos_param_args\" -- \"%s\" )\n", indent, paramName, currWord));
+                buff.append(format("%s      local IFS=$'\\n'\n", indent));
+                buff.append(format("%s      positionals=$( compgen -W \"${%s_pos_param_args[*]}\" -- \"%s\" )\n",
+                        indent, paramName, currWord));
             } else if (type.equals(File.class) || "java.nio.file.Path".equals(type.getName())) {
                 buff.append(format("%s    %s (( currIndex >= %d && currIndex <= %d )); then\n", indent, ifOrElif, min, max));
                 buff.append(format("%s      local IFS=$'\\n'\n", indent));
@@ -792,7 +794,9 @@ private static String generateOptionsCases(List<OptionSpec> argOptionFields, Str
             }
             if (option.completionCandidates() != null) {
                 buff.append(format("%s    %s)\n", indent, concat("|", option.names()))); // "    -u|--timeUnit)\n"
-                buff.append(format("%s      COMPREPLY=( $( compgen -W \"${%s_option_args}\" -- \"%s\" ) )\n", indent, bashify(option.paramLabel()), currWord));
+                buff.append(format("%s      local IFS=$'\\n'\n", indent));
+                buff.append(format("%s      COMPREPLY=( $( compgen -W \"${%s_option_args[*]}\" -- \"%s\" ) )\n", indent,
+                        bashify(option.paramLabel()), currWord));
                 buff.append(format("%s      return $?\n", indent));
                 buff.append(format("%s      ;;\n", indent));
             } else if (type.equals(File.class) || "java.nio.file.Path".equals(type.getName())) {
diff --git a/src/test/java/picocli/AutoCompleteTest.java b/src/test/java/picocli/AutoCompleteTest.java
index 8546ed074..ede423df5 100644
--- a/src/test/java/picocli/AutoCompleteTest.java
+++ b/src/test/java/picocli/AutoCompleteTest.java
@@ -15,22 +15,15 @@
  */
 package picocli;
 
-import org.hamcrest.MatcherAssert;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.contrib.java.lang.system.Assertion;
-import org.junit.contrib.java.lang.system.ExpectedSystemExit;
-import org.junit.contrib.java.lang.system.ProvideSystemProperty;
-import org.junit.contrib.java.lang.system.RestoreSystemProperties;
-import org.junit.contrib.java.lang.system.SystemErrRule;
-import org.junit.contrib.java.lang.system.SystemOutRule;
-import org.junit.rules.TestRule;
-import picocli.CommandLine.Command;
-import picocli.CommandLine.Model.CommandSpec;
-import picocli.CommandLine.Model.OptionSpec;
-import picocli.CommandLine.Model.PositionalParamSpec;
-import picocli.CommandLine.Option;
-import picocli.CommandLine.Parameters;
+import static java.lang.String.format;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.BufferedReader;
 import java.io.File;
@@ -53,11 +46,23 @@
 import java.util.Scanner;
 import java.util.concurrent.TimeUnit;
 
-import static java.lang.String.format;
-import static org.hamcrest.CoreMatchers.containsString;
-import static org.hamcrest.CoreMatchers.not;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.Assert.*;
+import org.hamcrest.MatcherAssert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.contrib.java.lang.system.Assertion;
+import org.junit.contrib.java.lang.system.ExpectedSystemExit;
+import org.junit.contrib.java.lang.system.ProvideSystemProperty;
+import org.junit.contrib.java.lang.system.RestoreSystemProperties;
+import org.junit.contrib.java.lang.system.SystemErrRule;
+import org.junit.contrib.java.lang.system.SystemOutRule;
+import org.junit.rules.TestRule;
+
+import picocli.CommandLine.Command;
+import picocli.CommandLine.Model.CommandSpec;
+import picocli.CommandLine.Model.OptionSpec;
+import picocli.CommandLine.Model.PositionalParamSpec;
+import picocli.CommandLine.Option;
+import picocli.CommandLine.Parameters;
 
 /**
  * Tests the scripts generated by AutoComplete.
@@ -93,7 +98,7 @@ public void run() {
     public void basic() throws Exception {
         String script = AutoComplete.bash("basicExample", new CommandLine(new BasicExample()));
         String expected = format(loadTextFromClasspath("/basic.bash"),
-                CommandLine.VERSION, spaced(TimeUnit.values()));
+                CommandLine.VERSION, concat("\" \"", TimeUnit.values()));
         assertEquals(expected, script);
     }
 
@@ -188,7 +193,7 @@ public void nestedSubcommands() throws Exception {
                 );
         String script = AutoComplete.bash("picocompletion-demo", hierarchy);
         String expected = format(loadTextFromClasspath("/picocompletion-demo_completion.bash"),
-                CommandLine.VERSION, spaced(TimeUnit.values()));
+                CommandLine.VERSION, concat("\" \"", TimeUnit.values()));
         assertEquals(expected, script);
     }
 
@@ -204,16 +209,16 @@ public void helpCommand() {
                 .addSubcommand(new CommandLine.HelpCommand());
         String script = AutoComplete.bash("picocompletion-demo-help", hierarchy);
         String expected = format(loadTextFromClasspath("/picocompletion-demo-help_completion.bash"),
-                CommandLine.VERSION, spaced(TimeUnit.values()));
+                CommandLine.VERSION, concat("\" \"", TimeUnit.values()));
         assertEquals(expected, script);
     }
 
-    private static String spaced(Object[] values) {
+    private static String concat(String infix, Object[] values) {
         StringBuilder result = new StringBuilder();
         for (Object value : values) {
-            result.append(value).append(' ');
+            result.append(value).append(infix);
         }
-        return result.toString().substring(0, result.length() - 1);
+        return result.toString().substring(0, result.length() - infix.length());
     }
 
     static String loadTextFromClasspath(String path) {
diff --git a/src/test/resources/bashify_completion.bash b/src/test/resources/bashify_completion.bash
index 679c78656..c0a5cebe8 100644
--- a/src/test/resources/bashify_completion.bash
+++ b/src/test/resources/bashify_completion.bash
@@ -136,13 +136,14 @@ function _picocli_bashify() {
   local commands=""
   local flag_opts=""
   local arg_opts="-x"
-  local _AB_C_option_args="1" # -x values
+  local _AB_C_option_args=("1") # -x values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -x)
-      COMPREPLY=( $( compgen -W "${_AB_C_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${_AB_C_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
   esac
diff --git a/src/test/resources/basic.bash b/src/test/resources/basic.bash
index ce12421b9..8bc3d0d16 100644
--- a/src/test/resources/basic.bash
+++ b/src/test/resources/basic.bash
@@ -136,13 +136,14 @@ function _picocli_basicExample() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
diff --git a/src/test/resources/picocompletion-demo-help_completion.bash b/src/test/resources/picocompletion-demo-help_completion.bash
index 3408e5681..d63a12a53 100644
--- a/src/test/resources/picocompletion-demo-help_completion.bash
+++ b/src/test/resources/picocompletion-demo-help_completion.bash
@@ -204,7 +204,7 @@ function _picocli_picocompletion-demo-help_sub1() {
   local commands=""
   local flag_opts=""
   local arg_opts="--num --str --candidates"
-  local str2_option_args="aaa bbb ccc" # --candidates values
+  local str2_option_args=("aaa" "bbb" "ccc") # --candidates values
 
   type compopt &>/dev/null && compopt +o default
 
@@ -216,7 +216,8 @@ function _picocli_picocompletion-demo-help_sub1() {
       return
       ;;
     --candidates)
-      COMPREPLY=( $( compgen -W "${str2_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${str2_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
   esac
@@ -238,7 +239,7 @@ function _picocli_picocompletion-demo-help_sub1alias() {
   local commands=""
   local flag_opts=""
   local arg_opts="--num --str --candidates"
-  local str2_option_args="aaa bbb ccc" # --candidates values
+  local str2_option_args=("aaa" "bbb" "ccc") # --candidates values
 
   type compopt &>/dev/null && compopt +o default
 
@@ -250,7 +251,8 @@ function _picocli_picocompletion-demo-help_sub1alias() {
       return
       ;;
     --candidates)
-      COMPREPLY=( $( compgen -W "${str2_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${str2_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
   esac
@@ -286,7 +288,7 @@ function _picocli_picocompletion-demo-help_sub2() {
       return $?
       ;;
   esac
-  local possibilities_pos_param_args="Aaa Bbb Ccc" # 0-0 values
+  local possibilities_pos_param_args=("Aaa" "Bbb" "Ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -295,7 +297,8 @@ function _picocli_picocompletion-demo-help_sub2() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$possibilities_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${possibilities_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -324,7 +327,7 @@ function _picocli_picocompletion-demo-help_sub2alias() {
       return $?
       ;;
   esac
-  local possibilities_pos_param_args="Aaa Bbb Ccc" # 0-0 values
+  local possibilities_pos_param_args=("Aaa" "Bbb" "Ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -333,7 +336,8 @@ function _picocli_picocompletion-demo-help_sub2alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$possibilities_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${possibilities_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -421,20 +425,21 @@ function _picocli_picocompletion-demo-help_sub2_subsub2() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -443,7 +448,8 @@ function _picocli_picocompletion-demo-help_sub2_subsub2() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub2" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -458,20 +464,21 @@ function _picocli_picocompletion-demo-help_sub2_sub2child2alias() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -480,7 +487,8 @@ function _picocli_picocompletion-demo-help_sub2_sub2child2alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child2-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -494,7 +502,7 @@ function _picocli_picocompletion-demo-help_sub2_subsub3() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -503,7 +511,8 @@ function _picocli_picocompletion-demo-help_sub2_subsub3() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub3" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
@@ -524,7 +533,7 @@ function _picocli_picocompletion-demo-help_sub2_sub2child3alias() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -533,7 +542,8 @@ function _picocli_picocompletion-demo-help_sub2_sub2child3alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child3-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
@@ -611,20 +621,21 @@ function _picocli_picocompletion-demo-help_sub2alias_subsub2() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -633,7 +644,8 @@ function _picocli_picocompletion-demo-help_sub2alias_subsub2() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub2" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -648,20 +660,21 @@ function _picocli_picocompletion-demo-help_sub2alias_sub2child2alias() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -670,7 +683,8 @@ function _picocli_picocompletion-demo-help_sub2alias_sub2child2alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child2-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -684,7 +698,7 @@ function _picocli_picocompletion-demo-help_sub2alias_subsub3() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -693,7 +707,8 @@ function _picocli_picocompletion-demo-help_sub2alias_subsub3() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub3" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
@@ -714,7 +729,7 @@ function _picocli_picocompletion-demo-help_sub2alias_sub2child3alias() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -723,7 +738,8 @@ function _picocli_picocompletion-demo-help_sub2alias_sub2child3alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child3-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
diff --git a/src/test/resources/picocompletion-demo_completion.bash b/src/test/resources/picocompletion-demo_completion.bash
index 996320ca0..95216cbd5 100644
--- a/src/test/resources/picocompletion-demo_completion.bash
+++ b/src/test/resources/picocompletion-demo_completion.bash
@@ -201,7 +201,7 @@ function _picocli_picocompletion-demo_sub1() {
   local commands=""
   local flag_opts=""
   local arg_opts="--num --str --candidates"
-  local str2_option_args="aaa bbb ccc" # --candidates values
+  local str2_option_args=("aaa" "bbb" "ccc") # --candidates values
 
   type compopt &>/dev/null && compopt +o default
 
@@ -213,7 +213,8 @@ function _picocli_picocompletion-demo_sub1() {
       return
       ;;
     --candidates)
-      COMPREPLY=( $( compgen -W "${str2_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${str2_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
   esac
@@ -235,7 +236,7 @@ function _picocli_picocompletion-demo_sub1alias() {
   local commands=""
   local flag_opts=""
   local arg_opts="--num --str --candidates"
-  local str2_option_args="aaa bbb ccc" # --candidates values
+  local str2_option_args=("aaa" "bbb" "ccc") # --candidates values
 
   type compopt &>/dev/null && compopt +o default
 
@@ -247,7 +248,8 @@ function _picocli_picocompletion-demo_sub1alias() {
       return
       ;;
     --candidates)
-      COMPREPLY=( $( compgen -W "${str2_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${str2_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
   esac
@@ -283,7 +285,7 @@ function _picocli_picocompletion-demo_sub2() {
       return $?
       ;;
   esac
-  local possibilities_pos_param_args="Aaa Bbb Ccc" # 0-0 values
+  local possibilities_pos_param_args=("Aaa" "Bbb" "Ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -292,7 +294,8 @@ function _picocli_picocompletion-demo_sub2() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$possibilities_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${possibilities_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -321,7 +324,7 @@ function _picocli_picocompletion-demo_sub2alias() {
       return $?
       ;;
   esac
-  local possibilities_pos_param_args="Aaa Bbb Ccc" # 0-0 values
+  local possibilities_pos_param_args=("Aaa" "Bbb" "Ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -330,7 +333,8 @@ function _picocli_picocompletion-demo_sub2alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$possibilities_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${possibilities_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -401,20 +405,21 @@ function _picocli_picocompletion-demo_sub2_subsub2() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -423,7 +428,8 @@ function _picocli_picocompletion-demo_sub2_subsub2() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub2" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -438,20 +444,21 @@ function _picocli_picocompletion-demo_sub2_sub2child2alias() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -460,7 +467,8 @@ function _picocli_picocompletion-demo_sub2_sub2child2alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child2-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -474,7 +482,7 @@ function _picocli_picocompletion-demo_sub2_subsub3() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -483,7 +491,8 @@ function _picocli_picocompletion-demo_sub2_subsub3() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub3" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
@@ -504,7 +513,7 @@ function _picocli_picocompletion-demo_sub2_sub2child3alias() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -513,7 +522,8 @@ function _picocli_picocompletion-demo_sub2_sub2child3alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child3-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
@@ -591,20 +601,21 @@ function _picocli_picocompletion-demo_sub2alias_subsub2() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -613,7 +624,8 @@ function _picocli_picocompletion-demo_sub2alias_subsub2() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub2" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -628,20 +640,21 @@ function _picocli_picocompletion-demo_sub2alias_sub2child2alias() {
   local commands=""
   local flag_opts=""
   local arg_opts="-u --timeUnit -t --timeout"
-  local timeUnit_option_args="%2$s" # --timeUnit values
+  local timeUnit_option_args=("%2$s") # --timeUnit values
 
   type compopt &>/dev/null && compopt +o default
 
   case ${prev_word} in
     -u|--timeUnit)
-      COMPREPLY=( $( compgen -W "${timeUnit_option_args}" -- "${curr_word}" ) )
+      local IFS=$'\n'
+      COMPREPLY=( $( compgen -W "${timeUnit_option_args[*]}" -- "${curr_word}" ) )
       return $?
       ;;
     -t|--timeout)
       return
       ;;
   esac
-  local str2_pos_param_args="aaa bbb ccc" # 0-0 values
+  local str2_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -650,7 +663,8 @@ function _picocli_picocompletion-demo_sub2alias_sub2child2alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child2-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$str2_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${str2_pos_param_args[*]}" -- "${curr_word}" )
     fi
     COMPREPLY=( $(compgen -W "${commands} ${positionals}" -- "${curr_word}") )
   fi
@@ -664,7 +678,7 @@ function _picocli_picocompletion-demo_sub2alias_subsub3() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -673,7 +687,8 @@ function _picocli_picocompletion-demo_sub2alias_subsub3() {
     local currIndex
     currIndex=$(currentPositionalIndex "subsub3" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames
@@ -694,7 +709,7 @@ function _picocli_picocompletion-demo_sub2alias_sub2child3alias() {
   local commands=""
   local flag_opts=""
   local arg_opts=""
-  local cands_pos_param_args="aaa bbb ccc" # 0-0 values
+  local cands_pos_param_args=("aaa" "bbb" "ccc") # 0-0 values
 
   if [[ "${curr_word}" == -* ]]; then
     COMPREPLY=( $(compgen -W "${flag_opts} ${arg_opts}" -- "${curr_word}") )
@@ -703,7 +718,8 @@ function _picocli_picocompletion-demo_sub2alias_sub2child3alias() {
     local currIndex
     currIndex=$(currentPositionalIndex "sub2child3-alias" "${arg_opts}" "${flag_opts}")
     if (( currIndex >= 0 && currIndex <= 0 )); then
-      positionals=$( compgen -W "$cands_pos_param_args" -- "${curr_word}" )
+      local IFS=$'\n'
+      positionals=$( compgen -W "${cands_pos_param_args[*]}" -- "${curr_word}" )
     elif (( currIndex >= 1 && currIndex <= 2 )); then
       local IFS=$'\n'
       type compopt &>/dev/null && compopt -o filenames