diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9ff28f451..170ce7a02 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -178,7 +178,7 @@ if (WIN32)
     # Bundled zlib
     add_subdirectory(dependencies/zlib-1.2.13)
     set(ZLIB_LIBRARY zlibstatic)
-    set(ZLIB_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/dependencies/zlib-1.2.13)
+    set(ZLIB_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/dependencies/zlib-1.2.13 CACHE PATH "zlib include dir")
 
     # Bundled libcurl
     set(CMAKE_CURL_INCLUDES)