diff --git a/sv.c b/sv.c
index 70a5110fbf42..1fb948bb26bd 100644
--- a/sv.c
+++ b/sv.c
@@ -5077,10 +5077,8 @@ Perl_sv_clear(pTHX_ register SV *sv)
 	}
     }
     if (type >= SVt_PVMG) {
-	HV *ourstash;
-	if ((type == SVt_PVMG || type == SVt_PVGV) &&
-	    (ourstash = OURSTASH(sv))) {
-	    SvREFCNT_dec(ourstash);
+	if ((type == SVt_PVMG || type == SVt_PVGV) && SvPAD_OUR(sv)) {
+	    SvREFCNT_dec(OURSTASH(sv));
 	} else if (SvMAGIC(sv))
 	    mg_free(sv);
 	if (type == SVt_PVMG && SvPAD_TYPED(sv))
@@ -10042,8 +10040,8 @@ Perl_sv_dup(pTHX_ const SV *sstr, CLONE_PARAMS* param)
 	       FIXME - instrument and check that assumption  */
 	    if (sv_type >= SVt_PVMG) {
 		HV *ourstash;
-		if ((sv_type == SVt_PVMG) && (ourstash = OURSTASH(dstr))) {
-		    OURSTASH_set(dstr, hv_dup_inc(ourstash, param));
+		if ((sv_type == SVt_PVMG) && SvPAD_OUR(dstr)) {
+		    OURSTASH_set(dstr, hv_dup_inc(OURSTASH(dstr), param));
 		} else if (SvMAGIC(dstr))
 		    SvMAGIC_set(dstr, mg_dup(SvMAGIC(dstr), param));
 		if (SvSTASH(dstr))
diff --git a/sv.h b/sv.h
index 71389c9d896d..ec6184ba66f2 100644
--- a/sv.h
+++ b/sv.h
@@ -1164,6 +1164,8 @@ the scalar's value cannot change unless written to.
 #    define SvMAGIC(sv)							\
 	(*({ SV *const _svi = (SV *) sv;				\
 	    assert(SvTYPE(_svi) >= SVt_PVMG);				\
+	    if(SvTYPE(_svi) == SVt_PVMG)				\
+		assert(!SvPAD_OUR(_svi));				\
 	    &(((XPVMG*) SvANY(_svi))->xmg_u.xmg_magic);			\
 	  }))
 #    define SvSTASH(sv)							\