diff --git a/src/userfunc.c b/src/userfunc.c
index ffc67ea..052923e 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -543,7 +543,7 @@
     if (len + 3 > bufsize)
 	return name;
 
-    mch_memmove(buf + 5, name + 3, len + 1);
+    mch_memmove(buf + 5, name + 3, len - 2);  // Include trailing NUL
     mch_memmove(buf, "<SNR>", 5);
     return buf;
 }