diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9f134cee..c7651448 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -542,10 +542,10 @@ if (ISLE_BUILD_APP)
         OUTPUT_STRIP_TRAILING_WHITESPACE
       )
       if(PIL_RESULT EQUAL 0 AND PIL_OUTPUT STREQUAL "pil")
-        set(PYTHON_PIL_AVAILABLE TRUE)
+        set(PYTHON_PIL_AVAILABLE TRUE CACHE BOOL "Is Python3 Pillow available?")
       else()
         message(STATUS "Python PIL not found, using pre-generated headers.")
-        set(PYTHON_PIL_AVAILABLE FALSE)
+        set(PYTHON_PIL_AVAILABLE FALSE CACHE BOOL "Is Python3 Pillow available?")
       endif()
     endif()
     if(PYTHON_PIL_AVAILABLE)