diff --git a/CMakeLists.txt b/CMakeLists.txt
index 254447b..6936fd2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -158,7 +158,7 @@ if (NOT (CMAKE_BUILD_TYPE STREQUAL Debug OR CMAKE_BUILD_TYPE STREQUAL RelWithDeb
     if (SELF_PACKER_FOR_EXECUTABLE MATCHES upx)
         set(SELF_PACKER_FOR_EXECUTABLE_FLAGS ${SELF_PACKER_FOR_EXECUTABLE_FLAGS} --ultra-brute --best)
     endif()
-    if (NOT SELF_PACKER_FOR_EXECUTABLE EQUAL "")
+    if (NOT SELF_PACKER_FOR_EXECUTABLE STREQUAL "SELF_PACKER_FOR_EXECUTABLE-NOTFOUND")
         add_custom_command(TARGET ${EXENAME} POST_BUILD COMMAND "${SELF_PACKER_FOR_EXECUTABLE}" ${SELF_PACKER_FOR_EXECUTABLE_FLAGS} $<TARGET_FILE:${EXENAME}> VERBATIM)
     endif()
 endif()