diff --git a/skeletons/INTEGER.h b/skeletons/INTEGER.h
index 8411bfc..9aa5457 100644
--- a/skeletons/INTEGER.h
+++ b/skeletons/INTEGER.h
@@ -57,6 +57,9 @@
 int asn_long2INTEGER(INTEGER_t *i, long l);
 int asn_ulong2INTEGER(INTEGER_t *i, unsigned long l);
 
+/* A a reified version of strtol(3) with nicer error reporting. */
+int asn_strtol(const char *str, const char *end, long *l);
+
 /*
  * Convert the integer value into the corresponding enumeration map entry.
  */