diff --git a/CMakeLists.txt b/CMakeLists.txt
index da6c8e5bb9f..26b632ac8ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -272,7 +272,8 @@ if(UA_ENABLE_CLANG_COV)
     if(UA_ENABLE_COVERAGE)
         message(FATAL_ERROR "Only either clang cov or normal coverage is allowed.")
     endif()
-    add_compile_options(-fprofile-instr-generate -fcoverage-mapping)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fprofile-instr-generate -fcoverage-mapping")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprofile-instr-generate -fcoverage-mapping")
 endif()
 
 if(UA_ENABLE_DISCOVERY_MULTICAST AND NOT UA_ENABLE_DISCOVERY)
@@ -550,12 +551,12 @@ endif()
 # Taken from https://stackoverflow.com/a/33266748
 include(CheckCCompilerFlag)
 function(check_add_cc_flag CC_FLAG)
-    list(FIND COMPILE_OPTIONS ${CC_FLAG} flag_already_set)
+    string(FIND "${CMAKE_C_FLAGS}" "${CC_FLAG}" flag_already_set)
     if(flag_already_set EQUAL -1)
         message(STATUS "Test CC flag ${CC_FLAG}")
-        check_c_compiler_flag(${CC_FLAG} flag_supported)
+        check_c_compiler_flag("${CC_FLAG}" flag_supported)
         if(flag_supported)
-            add_compile_options(${CC_FLAG})
+            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CC_FLAG}" PARENT_SCOPE)
         endif()
         unset(flag_supported CACHE)
     endif()
@@ -664,7 +665,8 @@ if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
         if(CMAKE_CXX_COMPILER_VERSION AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10.0)
             set(SANITIZER_FLAGS "${SANITIZER_FLAGS} -fsanitize-coverage=trace-pc-guard")
         endif()
-        add_compile_options(${SANITIZER_FLAGS})
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SANITIZER_FLAGS}")
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SANITIZER_FLAGS}")
     endif()
 
     if(NOT MINGW AND UA_ENABLE_HARDENING AND ((CMAKE_BUILD_TYPE STREQUAL "Release") OR (CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")))
@@ -683,25 +685,28 @@ if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
         # remove stack-protector with MinSizeRel
         if(CMAKE_BUILD_TYPE STREQUAL "MinSizeRel")
             check_add_cc_flag("-fno-stack-protector")
-            if(NOT WIN32 AND NOT CYGWIN AND NOT APPLE)
-                # these settings reduce the binary size by ~2kb
-                add_link_options(-Wl,-z,norelro -Wl,--hash-style=gnu -Wl,--build-id=none)
-            endif()
         endif()
         if(NOT OS9)
-            add_link_options(-s)
+            set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} -s")
+            set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -s")
         endif()
         if(APPLE)
-            add_link_options(-Wl,-dead_strip)
+            set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} -Wl,-dead_strip")
+            set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-dead_strip")
         else()
-            add_link_options(-Wl,--gc-sections)
+            set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} -Wl,--gc-sections")
+            set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--gc-sections")
+        endif()
+        if(NOT WIN32 AND NOT CYGWIN AND NOT APPLE)
+            # these settings reduce the binary size by ~2kb
+            set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} -Wl,-z,norelro -Wl,--hash-style=gnu -Wl,--build-id=none")
         endif()
     endif()
 endif()
 
 if(APPLE)
     set(CMAKE_MACOSX_RPATH 1)
-    add_compile_options(-D_DARWIN_C_SOURCE=1)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_DARWIN_C_SOURCE=1")
 endif()
 
 if(MSVC)