diff --git a/src/common.rs b/src/common.rs
index dd0fedeb3d6c..90d2b93dce43 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -122,6 +122,8 @@ bitflags! {
         const SYMBOLIC = 1 << 3;
         /// Escape : and =
         const SEPARATORS = 1 << 4;
+        /// Escape ,
+        const COMMA = 1 << 5;
     }
 }
 
@@ -183,6 +185,7 @@ pub fn escape_string(s: &wstr, style: EscapeStringStyle) -> WString {
 fn escape_string_script(input: &wstr, flags: EscapeFlags) -> WString {
     let escape_printables = !flags.contains(EscapeFlags::NO_PRINTABLES);
     let escape_separators = flags.contains(EscapeFlags::SEPARATORS);
+    let escape_comma = flags.contains(EscapeFlags::COMMA);
     let no_quoted = flags.contains(EscapeFlags::NO_QUOTED);
     let no_tilde = flags.contains(EscapeFlags::NO_TILDE);
     let no_qmark = feature_test(FeatureFlag::qmark_noglob);
@@ -300,6 +303,13 @@ fn escape_string_script(input: &wstr, flags: EscapeFlags) -> WString {
                 }
                 out.push(c);
             }
+            ',' => {
+                if escape_comma {
+                    need_escape = true;
+                    out.push('\\');
+                }
+                out.push(c);
+            }
 
             '&' | '$' | ' ' | '#' | '<' | '>' | '(' | ')' | '[' | ']' | '{' | '}' | '?' | '*'
             | '|' | ';' | '"' | '%' | '~' => {
diff --git a/src/expand.rs b/src/expand.rs
index 26ab7da403f0..b5934c48f0a6 100644
--- a/src/expand.rs
+++ b/src/expand.rs
@@ -8,9 +8,9 @@ use crate::builtins::shared::{
     STATUS_INVALID_ARGS, STATUS_NOT_EXECUTABLE, STATUS_READ_TOO_MUCH, STATUS_UNMATCHED_WILDCARD,
 };
 use crate::common::{
-    char_offset, charptr2wcstring, escape, escape_string_for_double_quotes, unescape_string,
-    valid_var_name_char, wcs2zstring, UnescapeFlags, UnescapeStringStyle, EXPAND_RESERVED_BASE,
-    EXPAND_RESERVED_END,
+    char_offset, charptr2wcstring, escape, escape_string, escape_string_for_double_quotes,
+    unescape_string, valid_var_name_char, wcs2zstring, EscapeFlags, EscapeStringStyle,
+    UnescapeFlags, UnescapeStringStyle, EXPAND_RESERVED_BASE, EXPAND_RESERVED_END,
 };
 use crate::complete::{CompleteFlags, Completion, CompletionList, CompletionReceiver};
 use crate::env::{EnvVar, Environment};
@@ -1096,7 +1096,7 @@ pub fn expand_cmdsubst(
     }
 
     for sub_item in sub_res {
-        let sub_item2 = escape(&sub_item);
+        let sub_item2 = escape_string(&sub_item, EscapeStringStyle::Script(EscapeFlags::COMMA));
         for tail_item in &*tail_expand {
             let mut whole_item = WString::new();
             whole_item.reserve(paren_begin + 1 + sub_item2.len() + 1 + tail_item.completion.len());
diff --git a/tests/checks/braces.fish b/tests/checks/braces.fish
index 061c3c45b640..93000750035e 100644
--- a/tests/checks/braces.fish
+++ b/tests/checks/braces.fish
@@ -48,3 +48,6 @@ world}
 end
 #CHECK: '{hello
 #CHECK: world}'
+
+echo {a(echo ,)b}
+#CHECK: {a,b}