diff --git a/VERSION b/VERSION
index 42246ba..fdd8146 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.311
+1.5.312
diff --git a/base/netcmp.c b/base/netcmp.c
index 38774c8..587b7b1 100644
--- a/base/netcmp.c
+++ b/base/netcmp.c
@@ -7544,6 +7544,11 @@ struct nlist *addproxies(struct hashlist *p, void *clientdata)
 	     }
 	     else {
 		lob = ob;
+		if (ob == NULL) {
+		    Fprintf(stdout, "Error:  Premature end of pin list on "
+			"instance %s.\n", firstpin->instance.name);
+		    break;
+		}
 		ob->type = i++;
 		ob = ob->next;
 	     }