diff --git a/libc/spec/gnu_ext.td b/libc/spec/gnu_ext.td
--- a/libc/spec/gnu_ext.td
+++ b/libc/spec/gnu_ext.td
@@ -61,7 +61,7 @@
          FunctionSpec<
             "memmem",
             RetValSpec<VoidPtr>,
-            [ArgSpec<ConstVoidPtr>, ArgSpec<SizeTType>, ArgSpec<ConstVoidPtr>, ArgSpec<SizeTType]
+            [ArgSpec<ConstVoidPtr>, ArgSpec<SizeTType>, ArgSpec<ConstVoidPtr>, ArgSpec<SizeTType>]
         >,
         FunctionSpec<
             "memrchr",