diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8240c803..1af7100e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,10 +33,18 @@ if(RCUTILS_NO_FILESYSTEM)
   add_compile_options(-DRCUTILS_NO_FILESYSTEM=1)
 endif()
 
+if(RCUTILS_NO_THREAD_SUPPORT)
+  add_compile_options(-DRCUTILS_NO_THREAD_SUPPORT=1)
+endif()
+
 if(RCUTILS_AVOID_DYNAMIC_ALLOCATION)
   add_compile_options(-DRCUTILS_AVOID_DYNAMIC_ALLOCATION=1)
 endif()
 
+# target_compile_definitions(${PROJECT_NAME} PRIVATE "RCUTILS_NO_FILESYSTEM") 
+# target_compile_definitions(${PROJECT_NAME} PRIVATE "RCUTILS_NO_THREAD_SUPPORT") 
+# target_compile_definitions(${PROJECT_NAME} PRIVATE "RCUTILS_AVOID_DYNAMIC_ALLOCATION") 
+
 configure_file (
     "${PROJECT_SOURCE_DIR}/include/rcutils/error_handling.h.in"
     "${PROJECT_BINARY_DIR}/include/rcutils/error_handling.h"
diff --git a/include/rcutils/macros.h b/include/rcutils/macros.h
index e254df46..11981683 100644
--- a/include/rcutils/macros.h
+++ b/include/rcutils/macros.h
@@ -28,7 +28,9 @@ extern "C"
 
 // Note: this block was migrated from rmw/macros.h
 // This block either sets RCUTILS_THREAD_LOCAL or RCUTILS_THREAD_LOCAL_PTHREAD.
-#if defined _WIN32 || defined __CYGWIN__
+#if RCUTILS_NO_THREAD_SUPPORT
+    #define RCUTILS_THREAD_LOCAL
+#elif defined _WIN32 || defined __CYGWIN__
 // Windows or Cygwin
   #define RCUTILS_THREAD_LOCAL __declspec(thread)
 #elif defined __APPLE__
diff --git a/src/time_unix.c b/src/time_unix.c
index 028fb453..ea52711d 100644
--- a/src/time_unix.c
+++ b/src/time_unix.c
@@ -39,7 +39,7 @@ extern "C"
 // This id an appropriate check for clock_gettime() according to:
 //   http://man7.org/linux/man-pages/man2/clock_gettime.2.html
 # if !defined(_POSIX_TIMERS) || !_POSIX_TIMERS
-#  error no monotonic clock function available
+#  warning no monotonic clock function available
 # endif  // !defined(_POSIX_TIMERS) || !_POSIX_TIMERS
 #endif  // !defined(__MACH__)