3 files changed, 6 insertions, 4 deletions
diff --git a/embed.fnc b/embed.fnc
index c62948841f..af029ad1bd 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -316,7 +316,7 @@ ApdR	|SV*	|gv_const_sv	|NN GV* gv
 ApdRn	|SV*	|cv_const_sv	|NULLOK const CV *const cv
 pRn	|SV*	|cv_const_sv_or_av|NULLOK const CV *const cv
 : Used in pad.c
-pR	|SV*	|op_const_sv	|NULLOK const OP* o|NULLOK CV* cv \
+pR	|SV*	|op_const_sv	|NN const OP* o|NULLOK CV* cv \
 				|NULLOK CV *outside
 Apd	|SV *	|cv_name	|NN CV *cv|NULLOK SV *sv|U32 flags
 Apd	|void	|cv_undef	|NN CV* cv
diff --git a/op.c b/op.c
index 3b98a32c57..4821fbdc22 100644
--- a/op.c
+++ b/op.c
@@ -7713,8 +7713,7 @@ Perl_op_const_sv(pTHX_ const OP *o, CV *cv, CV *outcv)
 {
     SV *sv = NULL;
 
-    if (!o)
-	return NULL;
+    PERL_ARGS_ASSERT_OP_CONST_SV;
 
     if (o->op_type == OP_LINESEQ && cLISTOPo->op_first)
 	o = OP_SIBLING(cLISTOPo->op_first);
diff --git a/proto.h b/proto.h
index c88bd0a640..19c7d292bc 100644
--- a/proto.h
+++ b/proto.h
@@ -3197,7 +3197,10 @@ PERL_CALLCONV void	Perl_op_clear(pTHX_ OP* o)
 	assert(o)
 
 PERL_CALLCONV SV*	Perl_op_const_sv(pTHX_ const OP* o, CV* cv, CV *outside)
-			__attribute__warn_unused_result__;
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+#define PERL_ARGS_ASSERT_OP_CONST_SV	\
+	assert(o)
 
 PERL_CALLCONV OP*	Perl_op_contextualize(pTHX_ OP* o, I32 context)
 			__attribute__nonnull__(pTHX_1);