diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8507b7fb15..c1705f9441 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1036,9 +1036,10 @@ endif()
 # validating custom.bat/sh for changes
 if (EXISTS "${CMAKE_BINARY_DIR}/custom.${SCRIPT_EXT}" AND EXISTS "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}")
   file (READ "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}" CUSTOM_CONTENT)
-  if (NOT "${CUSTOM_CONTENT}" MATCHES "${ADDITIONAL_CUSTOM_CONTENT}")
+  string(FIND "${CUSTOM_CONTENT}" "${ADDITIONAL_CUSTOM_CONTENT}" pos)
+  if (pos EQUAL -1)
     set (CUSTOM_CONTENT "${CUSTOM_CONTENT} ${ADDITIONAL_CUSTOM_CONTENT}")
-    OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.${SCRIPT_EXT}.main" "custom.${SCRIPT_EXT}" "custom.${SCRIPT_EXT}" "${CUSTOM_CONTENT}")
+    OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.${SCRIPT_EXT}.main" "custom.${SCRIPT_EXT}" "custom.${SCRIPT_EXT}" "${INSTALL_DIR_SCRIPT}")
   endif()
 else()
   OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.${SCRIPT_EXT}.main" "custom.${SCRIPT_EXT}" "custom.${SCRIPT_EXT}" "${INSTALL_DIR_SCRIPT}")