diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6b3e5b3..966ddb3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -134,7 +134,7 @@ else (USE_EXT_GD)
 	endif (ENABLE_ICONV)
 
 	IF (ENABLE_WEBP)
-		FIND_PACKAGE(WEBP REQUIRED)
+		FIND_PACKAGE(WebP CONFIG REQUIRED)
 	ENDIF (ENABLE_WEBP)
 
 	IF (ENABLE_HEIF)
diff --git a/src/config.h.cmake b/src/config.h.cmake
index 0542942..e9cfde1 100644
--- a/src/config.h.cmake
+++ b/src/config.h.cmake
@@ -142,3 +142,8 @@
 
 /* Version number of package */
 #cmakedefine VERSION
+
+#ifdef _MSC_VER
+    #define ssize_t SSIZE_T
+    #define SSIZE_MAX MAXSSIZE_T
+#endif
\ No newline at end of file