diff --git a/tools/test_build/test_build.ino b/tools/test_build/test_build.ino
index 051a3c01..c29294d6 100644
--- a/tools/test_build/test_build.ino
+++ b/tools/test_build/test_build.ino
@@ -4,6 +4,8 @@
  *
  **************************************************************/
 
+#define TINY_GSM_MODEM_SIM800
+
 #include <TinyGsmClient.h>
 
 TinyGsm modem(Serial);