diff --git a/core/tests/regression_tests.rs b/core/tests/regression_tests.rs
index 5c413de7f..696149a11 100644
--- a/core/tests/regression_tests.rs
+++ b/core/tests/regression_tests.rs
@@ -155,6 +155,7 @@ swf_tests! {
     (xml_inspect_createmethods, "avm1/xml_inspect_createmethods", 1),
     (xml_inspect_parsexml, "avm1/xml_inspect_parsexml", 1),
     (funky_function_calls, "avm1/funky_function_calls", 1),
+    (undefined_to_string_swf6, "avm1/undefined_to_string_swf6", 1),
 }
 
 // TODO: These tests have some inaccuracies currently, so we use approx_eq to test that numeric values are close enough.
diff --git a/core/tests/swfs/avm1/undefined_to_string_swf6/output.txt b/core/tests/swfs/avm1/undefined_to_string_swf6/output.txt
new file mode 100644
index 000000000..c69cfd912
--- /dev/null
+++ b/core/tests/swfs/avm1/undefined_to_string_swf6/output.txt
@@ -0,0 +1,4 @@
+undefined
+
+
+undefined
diff --git a/core/tests/swfs/avm1/undefined_to_string_swf6/test.fla b/core/tests/swfs/avm1/undefined_to_string_swf6/test.fla
new file mode 100644
index 000000000..3b125fbb2
Binary files /dev/null and b/core/tests/swfs/avm1/undefined_to_string_swf6/test.fla differ
diff --git a/core/tests/swfs/avm1/undefined_to_string_swf6/test.swf b/core/tests/swfs/avm1/undefined_to_string_swf6/test.swf
new file mode 100644
index 000000000..8271bdc42
Binary files /dev/null and b/core/tests/swfs/avm1/undefined_to_string_swf6/test.swf differ