diff --git a/TESTS/secure_time/library_api/main.cpp b/TESTS/secure_time/library_api/main.cpp
index 4aff6e4987..91f386f5ab 100644
--- a/TESTS/secure_time/library_api/main.cpp
+++ b/TESTS/secure_time/library_api/main.cpp
@@ -13,6 +13,7 @@
  * limitations under the License.
  */
 
+#include "mbed.h"
 #include "secure_time_utils.h"
 #include "greentea-client/test_env.h"
 #include "unity.h"