diff --git a/CMakeLists.txt b/CMakeLists.txt
index 83a75b44f..b574c0b1e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1663,6 +1663,7 @@ if (WIN32)
 
   if (DEFINED ENV{SFOX_DIR})
     set(sfox_dir "$ENV{SFOX_DIR}")
+    string(REPLACE "\\" "/" sfox_dir "${sfox_dir}")
   else ()
     set(sfox_dir lib/superfox/win)
   endif ()