diff --git a/crypto/x509/v3_lib.c b/crypto/x509/v3_lib.c
index 6b12975761..322a210af5 100644
--- a/crypto/x509/v3_lib.c
+++ b/crypto/x509/v3_lib.c
@@ -150,7 +150,7 @@ const X509V3_EXT_METHOD *X509V3_EXT_get_nid(int nid) {
 
 const X509V3_EXT_METHOD *X509V3_EXT_get(const X509_EXTENSION *ext) {
   int nid;
-  if ((nid = OBJ_obj2nid(ext->object)) == NID_undef) {
+  if (ext == NULL || (nid = OBJ_obj2nid(ext->object)) == NID_undef) {
     return NULL;
   }
   return X509V3_EXT_get_nid(nid);