diff --git a/tool/rbs_skip_tests b/tool/rbs_skip_tests
index 68b19085a0..1c0397bf22 100644
--- a/tool/rbs_skip_tests
+++ b/tool/rbs_skip_tests
@@ -31,3 +31,5 @@ NetInstanceTest depending on external resources
 TestHTTPRequest depending on external resources
 TestSingletonNetHTTPResponse depending on external resources
 TestInstanceNetHTTPResponse depending on external resources
+
+test_bytesplice(StringInstanceTest) Assertion Failed: ../src/internal/class.h:156:RCLASS_SET_M_TBL:!RB_OBJ_PROMOTED(klass)