diff --git a/src/java.base/share/classes/java/lang/Runtime.java b/src/java.base/share/classes/java/lang/Runtime.java
index 7948ebffb6372..2288aca4d1114 100644
--- a/src/java.base/share/classes/java/lang/Runtime.java
+++ b/src/java.base/share/classes/java/lang/Runtime.java
@@ -290,6 +290,12 @@ public void halt(int status) {
      * behaves in exactly the same way as the invocation
      * {@link #exec(String, String[], File) exec}{@code (command, null, null)}.
      *
+     * @deprecated This method is error-prone and should not be used, the corresponding method
+     * {@link #exec(String[])} or {@link ProcessBuilder} should be used instead.
+     * The command string is broken into tokens using only whitespace characters.
+     * For an argument with an embedded space, such as a filename, this can cause problems
+     * as the token does not include the full filename.
+     *
      * @param   command   a specified system command.
      *
      * @return  A new {@link Process} object for managing the subprocess
@@ -311,6 +317,7 @@ public void halt(int status) {
      * @see     #exec(String[], String[], File)
      * @see     ProcessBuilder
      */
+    @Deprecated(since="18")
     public Process exec(String command) throws IOException {
         return exec(command, null, null);
     }
@@ -324,6 +331,12 @@ public Process exec(String command) throws IOException {
      * behaves in exactly the same way as the invocation
      * {@link #exec(String, String[], File) exec}{@code (command, envp, null)}.
      *
+     * @deprecated This method is error-prone and should not be used, the corresponding method
+     * {@link #exec(String[], String[])} or {@link ProcessBuilder} should be used instead.
+     * The command string is broken into tokens using only whitespace characters.
+     * For an argument with an embedded space, such as a filename, this can cause problems
+     * as the token does not include the full filename.
+     *
      * @param   command   a specified system command.
      *
      * @param   envp      array of strings, each element of which
@@ -352,6 +365,7 @@ public Process exec(String command) throws IOException {
      * @see     #exec(String[], String[], File)
      * @see     ProcessBuilder
      */
+    @Deprecated(since="18")
     public Process exec(String command, String[] envp) throws IOException {
         return exec(command, envp, null);
     }
@@ -374,6 +388,12 @@ public Process exec(String command, String[] envp) throws IOException {
      * produced by the tokenizer are then placed in the new string
      * array {@code cmdarray}, in the same order.
      *
+     * @deprecated This method is error-prone and should not be used, the corresponding method
+     * {@link #exec(String[], String[], File)} or {@link ProcessBuilder} should be used instead.
+     * The command string is broken into tokens using only whitespace characters.
+     * For an argument with an embedded space, such as a filename, this can cause problems
+     * as the token does not include the full filename.
+     *
      * @param   command   a specified system command.
      *
      * @param   envp      array of strings, each element of which
@@ -406,6 +426,7 @@ public Process exec(String command, String[] envp) throws IOException {
      * @see     ProcessBuilder
      * @since 1.3
      */
+    @Deprecated(since="18")
     public Process exec(String command, String[] envp, File dir)
         throws IOException {
         if (command.isEmpty())
diff --git a/test/jdk/java/lang/ProcessBuilder/Zombies.java b/test/jdk/java/lang/ProcessBuilder/Zombies.java
index 25299608ea70d..5a98250bce712 100644
--- a/test/jdk/java/lang/ProcessBuilder/Zombies.java
+++ b/test/jdk/java/lang/ProcessBuilder/Zombies.java
@@ -49,17 +49,20 @@ public static void main(String[] args) throws Throwable {
         final Runtime rt = Runtime.getRuntime();
 
         try {
-            rt.exec("no-such-file");
+            String[] cmd = {"no-such-file"};
+            rt.exec(cmd);
             throw new Error("expected IOException not thrown");
         } catch (IOException expected) {/* OK */}
 
         try {
-            rt.exec(".");
+            String[] cmd = {"."};
+            rt.exec(cmd);
             throw new Error("expected IOException not thrown");
         } catch (IOException expected) {/* OK */}
 
         try {
-            rt.exec(TrueCommand, null, new File("no-such-dir"));
+            String[] cmd = {TrueCommand};
+            rt.exec(cmd, null, new File("no-such-dir"));
             throw new Error("expected IOException not thrown");
         } catch (IOException expected) {/* OK */}
 
diff --git a/test/jdk/java/lang/RuntimeTests/exec/BadEnvp.java b/test/jdk/java/lang/RuntimeTests/exec/BadEnvp.java
index 1a5c9f8c9be63..d216b65a84094 100644
--- a/test/jdk/java/lang/RuntimeTests/exec/BadEnvp.java
+++ b/test/jdk/java/lang/RuntimeTests/exec/BadEnvp.java
@@ -29,6 +29,7 @@
 
 public class BadEnvp {
 
+    @SuppressWarnings("deprecation")
     public static void main(String[] args) throws Exception {
         Runtime r = Runtime.getRuntime();
         java.io.File dir = new java.io.File(".");
diff --git a/test/jdk/java/lang/RuntimeTests/exec/ExecWithDir.java b/test/jdk/java/lang/RuntimeTests/exec/ExecWithDir.java
index a52e2221ca883..4f2b723d18085 100644
--- a/test/jdk/java/lang/RuntimeTests/exec/ExecWithDir.java
+++ b/test/jdk/java/lang/RuntimeTests/exec/ExecWithDir.java
@@ -41,7 +41,7 @@ public static void main(String args[]) throws Exception {
         }
         UnixCommands.ensureCommandsAvailable("true");
 
-        final String trueCmd = UnixCommands.findCommand("true");
+        final String[] trueCmd = {UnixCommands.findCommand("true")};
         File dir = new File(".");
         for (int i = 1; i <= N; i++) {
             System.out.print(i);
diff --git a/test/jdk/java/lang/RuntimeTests/exec/SetCwd.java b/test/jdk/java/lang/RuntimeTests/exec/SetCwd.java
index 347c4d0eae378..a457b48b5e55f 100644
--- a/test/jdk/java/lang/RuntimeTests/exec/SetCwd.java
+++ b/test/jdk/java/lang/RuntimeTests/exec/SetCwd.java
@@ -62,6 +62,7 @@ public void testRuntimeExecWithArray() throws Exception {
     @Test
     public void testRuntimeExecWithString() throws Exception {
         String cmd = String.join(" ", CMD_ARRAY);
+        @SuppressWarnings("deprecation")
         Process process = Runtime.getRuntime().exec(cmd, null,
                 new File(TEST_CLASSES));
         verifyProcessOutput(process);