diff --git a/sup b/sup
index ecd4687..e22f5f1 100755
--- a/sup
+++ b/sup
@@ -163,6 +163,11 @@ main() {
 			}
 		else
 			file="$target"
+
+			[[ -f "$file" ]] || {
+				sup.err "No such file: ${file}"
+				return 1
+			}
 		fi
 	fi