diff --git a/third_party/fpattern/CMakeLists.txt b/third_party/fpattern/CMakeLists.txt
index d809812..7f813a8 100644
--- a/third_party/fpattern/CMakeLists.txt
+++ b/third_party/fpattern/CMakeLists.txt
@@ -20,7 +20,7 @@ add_library(fpattern STATIC
     "${fpattern_SOURCE_DIR}/fpattern.h"
 )
 
-if(APPLE)
+if(NOT WIN32)
     target_compile_definitions(fpattern PRIVATE
         "-Dunix"
     )