1 files changed, 2 insertions, 1 deletions
diff --git a/op.c b/op.c
index baa62fb927..eba79ef16f 100644
--- a/op.c
+++ b/op.c
@@ -4165,9 +4165,10 @@ Perl_cv_undef(pTHX_ CV *cv)
 
 #ifdef USE_ITHREADS
     if (CvFILE(cv) && !CvXSUB(cv)) {
+	/* for XSUBs CvFILE point directly to static memory; __FILE__ */
 	Safefree(CvFILE(cv));
-	CvFILE(cv) = 0;
     }
+    CvFILE(cv) = 0;
 #endif
 
     if (!CvXSUB(cv) && CvROOT(cv)) {