diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index da499c9..a2e53ad 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -7347,6 +7347,11 @@
     char_u	*arg = eap->arg;
     char_u	*p;
 
+    if (!isdigit(*arg))
+    {
+	semsg(_(e_invarg2), arg);
+	return;
+    }
     w = getdigits(&arg);
     arg = skipwhite(arg);
     p = arg;