diff --git a/profiles/osapi/modern.h b/profiles/osapi/modern.h
index c756844..da13d99 100644
--- a/profiles/osapi/modern.h
+++ b/profiles/osapi/modern.h
@@ -1,6 +1,15 @@
 #ifndef PY_OSAPI_MODERN_H
 #define PY_OSAPI_MODERN_H
 
+/* atomics */
+#ifdef  __ATOMIC_ACQUIRE
+#define HAVE_BUILTIN_ATOMIC             1
+#endif
+
+#ifdef  HAVE_STDATOMIC_H
+#define HAVE_STD_ATOMIC                 1
+#endif
+
 /* stdc headers */
 #define STDC_HEADERS                    1
 
diff --git a/project/config/cfgdefs.sh b/project/config/cfgdefs.sh
index 567e6cf..750de3a 100644
--- a/project/config/cfgdefs.sh
+++ b/project/config/cfgdefs.sh
@@ -80,6 +80,7 @@ cfgdefs_perform_common_tests()
 {
 	# headers
 	cfgtest_header_absence  'stropts.h'
+	cfgtest_header_presence 'stdatomic.h'
 	cfgtest_header_presence 'endian.h'
 	cfgtest_header_presence 'net/if.h'
 	cfgtest_header_presence 'sched.h'