diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -51,8 +51,15 @@ set(SRC_FILES
     src/CascRootFile_WoW.cpp
 )
 
+if(WIN32)
+    set(SRC_FILES ${SRC_FILES}
+        src/DllMain.c
+        src/DllMain.def
+    )
+endif()
+
 set(LINK_LIBS)
-find_package(ZLIB)
+find_package(ZLIB REQUIRED)
 if (ZLIB_FOUND)
     set(LINK_LIBS ${LINK_LIBS} ZLIB::ZLIB)
     add_definitions(-DCASC_USE_SYSTEM_ZLIB)