diff --git a/boa_engine/src/bytecompiler.rs b/boa_engine/src/bytecompiler.rs
index 57e0d7f6599..cb5a3b45122 100644
--- a/boa_engine/src/bytecompiler.rs
+++ b/boa_engine/src/bytecompiler.rs
@@ -1480,11 +1480,12 @@ impl<'b> ByteCompiler<'b> {
                             break;
                         }
                     }
-                    assert!(
-                        found,
-                        "Undefined label '{}'",
-                        self.interner().resolve_expect(label_name)
-                    );
+                    if !found {
+                        return self.context.throw_syntax_error(format!(
+                            "Undefined label '{}'",
+                            self.interner().resolve_expect(label_name)
+                        ));
+                    }
                 } else {
                     self.jump_info
                         .last_mut()
diff --git a/boa_engine/src/tests.rs b/boa_engine/src/tests.rs
index 1d8176012a0..beb7d71af91 100644
--- a/boa_engine/src/tests.rs
+++ b/boa_engine/src/tests.rs
@@ -431,15 +431,14 @@ fn for_loop_iteration_variable_does_not_leak() {
 }
 
 #[test]
-#[should_panic]
 fn test_invalid_break_target() {
     let src = r#"
-        while (false) {
+        while (true) {
           break nonexistent;
         }
         "#;
 
-    let _ = &exec(src);
+    assert!(matches!(Context::default().eval(src.as_bytes()), Err(_)));
 }
 
 #[test]