diff --git a/setup.py b/setup.py
index cd9a549..440043c 100644
--- a/setup.py
+++ b/setup.py
@@ -23,7 +23,7 @@ link_args = []
 
 if os.name == 'posix' and sys.platform != 'darwin':
     compiler = new_compiler()
-    if compiler.has_function('timer_create', libraries=('rt', )):
+    if compiler.has_function('timer_create', libraries=('rt', ), includes=["signal.h", "time.h"]):
         user_macros.append(('LIB_RT_AVAILABLE', '1'))
         user_libraries.append('rt')
 if _DEBUG: