diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 804d742..40d6605 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -3527,7 +3527,11 @@
 	    {
 		/* NFA_ZEND -> NFA_END_PATTERN -> NFA_SKIP -> what follows. */
 		skip = alloc_state(NFA_SKIP, NULL, NULL);
+		if (skip == NULL)
+		    goto theend;
 		zend = alloc_state(NFA_ZEND, s1, NULL);
+		if (zend == NULL)
+		    goto theend;
 		s1->out= skip;
 		patch(e.out, zend);
 		PUSH(frag(s, list1(&skip->out)));