diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index fa0db2c..36affd6 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2451,7 +2451,7 @@
     const char *Option = *it;
 
     // We only remove warning options.
-    if (!strncmp(Option, "-W", 3)) {
+    if (!strncmp(Option, "-W", 2)) {
       ++it;
       continue;
     }