diff --git a/CMakeLists.txt b/CMakeLists.txt
index d426e1da..5f1a4044 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,7 +7,7 @@ endif()
 
 string(TOLOWER "${CMAKE_BUILD_TYPE}" BUILD_TYPE_LOWER_CASE)
 
-set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/tools/cmake")
+list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/tools/cmake")
 find_package(PythonInterp REQUIRED)
 find_package(Git)
 include(AssignSourceGroup)
@@ -416,17 +416,17 @@ if(NOT UA_COMPILE_AS_CXX AND (CMAKE_COMPILER_IS_GNUCC OR "x${CMAKE_C_COMPILER_ID
 
         # IPO requires too much memory for unit tests
         # GCC docu recommends to compile all files with the same options, therefore ignore it completely
-        if(NOT UA_BUILD_UNIT_TESTS)
-            # needed to check if IPO is supported (check needs cmake > 3.9)
-            if("${CMAKE_VERSION}" VERSION_GREATER 3.9)
-                cmake_policy(SET CMP0069 NEW) # needed as long as required cmake < 3.9
-                include(CheckIPOSupported)
-                check_ipo_supported(RESULT CC_HAS_IPO) # Inter Procedural Optimization / Link Time Optimization (should be same as -flto)
-                if(CC_HAS_IPO)
-                    set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
-                endif()
-            endif()
-        endif()
+        #if(NOT UA_BUILD_UNIT_TESTS)
+        #    # needed to check if IPO is supported (check needs cmake > 3.9)
+        #    if("${CMAKE_VERSION}" VERSION_GREATER 3.9)
+        #        cmake_policy(SET CMP0069 NEW) # needed as long as required cmake < 3.9
+        #        include(CheckIPOSupported)
+        #        check_ipo_supported(RESULT CC_HAS_IPO) # Inter Procedural Optimization / Link Time Optimization (should be same as -flto)
+        #        if(CC_HAS_IPO)
+        #            set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
+        #        endif()
+        #    endif()
+        #endif()
     endif()
 
     if(UA_ENABLE_AMALGAMATION)