diff --git a/cli/src/commands/squash.rs b/cli/src/commands/squash.rs
index 74ae40d38..cd4135177 100644
--- a/cli/src/commands/squash.rs
+++ b/cli/src/commands/squash.rs
@@ -27,6 +27,7 @@ use crate::cli_util::DiffSelector;
 use crate::cli_util::RevisionArg;
 use crate::cli_util::WorkspaceCommandTransaction;
 use crate::command_error::user_error;
+use crate::command_error::user_error_with_hint;
 use crate::command_error::CommandError;
 use crate::description_util::combine_messages;
 use crate::description_util::join_message_paragraphs;
@@ -117,7 +118,10 @@ pub(crate) fn cmd_squash(
             .resolve_single_rev(args.revision.as_ref().unwrap_or(&RevisionArg::AT))?;
         let mut parents: Vec<_> = source.parents().try_collect()?;
         if parents.len() != 1 {
-            return Err(user_error("Cannot squash merge commits"));
+            return Err(user_error_with_hint(
+                "Cannot squash merge commits without a specified destination",
+                "Use `--into` to specify which parent to squash into",
+            ));
         }
         sources = vec![source];
         destination = parents.pop().unwrap();
diff --git a/cli/tests/test_squash_command.rs b/cli/tests/test_squash_command.rs
index 6b23345e1..562079108 100644
--- a/cli/tests/test_squash_command.rs
+++ b/cli/tests/test_squash_command.rs
@@ -100,9 +100,10 @@ fn test_squash() {
     ◆  000000000000 (empty)
     "###);
     let stderr = test_env.jj_cmd_failure(&repo_path, &["squash"]);
-    insta::assert_snapshot!(stderr, @r###"
-    Error: Cannot squash merge commits
-    "###);
+    insta::assert_snapshot!(stderr, @r#"
+    Error: Cannot squash merge commits without a specified destination
+    Hint: Use `--into` to specify which parent to squash into
+    "#);
 
     // Can squash into a merge commit
     test_env.jj_cmd_ok(&repo_path, &["new", "e"]);