diff --git a/CMakeLists.txt b/CMakeLists.txt
index d85d451af..8c793474a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2616,6 +2616,7 @@ if(TOOLS)
       string(REGEX REPLACE "\\.cpp$" "" TOOL "${T}")
       set(TOOL_DEPS ${DEPS})
       set(TOOL_LIBS ${LIBS})
+      unset(EXTRA_TOOL_SRC)
       if(TOOL MATCHES "^(dilate|map_convert_07|map_create_pixelart|map_optimize|map_extract|map_replace_image)$")
         list(APPEND TOOL_INCLUDE_DIRS ${PNG_INCLUDE_DIRS})
         list(APPEND TOOL_DEPS $<TARGET_OBJECTS:engine-gfx>)