diff --git a/src/lists.rs b/src/lists.rs
index ffb92d3a83cbf..97592f893a520 100644
--- a/src/lists.rs
+++ b/src/lists.rs
@@ -612,7 +612,7 @@ pub fn extract_post_comment(
         post_snippet[1..].trim_matches(white_space)
     } else if post_snippet.starts_with(separator) {
         post_snippet[separator.len()..].trim_matches(white_space)
-    } else if post_snippet.ends_with(',') {
+    } else if post_snippet.ends_with(',') && !post_snippet.trim().starts_with("//") {
         post_snippet[..(post_snippet.len() - 1)].trim_matches(white_space)
     } else {
         post_snippet
diff --git a/tests/source/issue-3532.rs b/tests/source/issue-3532.rs
new file mode 100644
index 0000000000000..ec0c01610cd4f
--- /dev/null
+++ b/tests/source/issue-3532.rs
@@ -0,0 +1,7 @@
+fn foo(a: T) {
+    match a {
+1 => {}
+    0 => {}
+    // _ => panic!("doesn't format!"),
+    }
+}
diff --git a/tests/target/issue-3532.rs b/tests/target/issue-3532.rs
new file mode 100644
index 0000000000000..f41902620cd19
--- /dev/null
+++ b/tests/target/issue-3532.rs
@@ -0,0 +1,6 @@
+fn foo(a: T) {
+    match a {
+        1 => {}
+        0 => {} // _ => panic!("doesn't format!"),
+    }
+}