1 files changed, 1 insertions, 1 deletions
diff --git a/error.c b/error.c
index bdc38ecb55..4c8aea5964 100644
--- a/error.c
+++ b/error.c
@@ -254,7 +254,7 @@ exc_inspect(exc)
 
     klass = CLASS_OF(exc);
     if (RSTRING(exc)->len == 0) {
-	return rb_class_path(klass);
+	return str_dup(rb_class_path(klass));
     }
 
     str = str_new2("#<");