1 files changed, 5 insertions, 0 deletions
diff --git a/pp_ctl.c b/pp_ctl.c
index 564e437cb5..d5027204d4 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -128,6 +128,7 @@ PP(pp_regcomp)
 	STRLEN len;
 	const char *t = SvOK(tmpstr) ? SvPV_const(tmpstr, len) : "";
 	re = PM_GETRE(pm);
+	assert (re != (REGEXP*) &PL_sv_undef);
 
 	/* Check against the last compiled regexp. */
 	if (!re || !RX_PRECOMP(re) || RX_PRELEN(re) != len ||
@@ -137,7 +138,11 @@ PP(pp_regcomp)
             U32 pm_flags = pm->op_pmflags & PMf_COMPILETIME;
 	    if (re) {
 	        ReREFCNT_dec(re);
+#ifdef USE_ITHREADS
+		PM_SETRE(pm, (REGEXP*) &PL_sv_undef);
+#else
 		PM_SETRE(pm, NULL);	/* crucial if regcomp aborts */
+#endif
 	    } else if (PL_curcop->cop_hints_hash) {
 	        SV *ptr = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash, 0,
 				       "regcomp", 7, 0, 0);