diff --git a/meson.build b/meson.build
index 2c1f1059..e6fe6d5e 100644
--- a/meson.build
+++ b/meson.build
@@ -28,8 +28,10 @@ openrtx_src = ['openrtx/src/bootstrap.c',
 ## Replace main executable with platform test
 if get_option('test') != ''
   openrtx_src += 'tests/platform/'+get_option('test')+'.c'
+  openrtx_def  = {'RUN_TESTSUITE': ''}
 else
   openrtx_src += 'openrtx/src/main.c'
+  openrtx_def  = {}
 endif
 
 openrtx_inc = ['openrtx/include',
@@ -86,7 +88,7 @@ inc = openrtx_inc + rtos_inc + minmea_inc
 ##
 ## Definitions
 ##
-def = {'DONT_USE_CMSIS_INIT': ''}
+def = openrtx_def + {'DONT_USE_CMSIS_INIT': ''}
 
 ##
 ## MCU-dependent sources and includes
diff --git a/openrtx/src/bootstrap.c b/openrtx/src/bootstrap.c
index 2cc9c6fe..1d241651 100644
--- a/openrtx/src/bootstrap.c
+++ b/openrtx/src/bootstrap.c
@@ -29,7 +29,13 @@ int main(int argc, char *argv[]);
 /*
  * OS startup task, will call main() when all initialisations are done.
  */
+
+#ifdef RUN_TESTSUITE
+#define START_TSK_STKSIZE 4096/sizeof(CPU_STK)
+#else
 #define START_TSK_STKSIZE 512/sizeof(CPU_STK)
+#endif
+
 static OS_TCB  startTCB;
 static CPU_STK startStk[START_TSK_STKSIZE];
 static void startTask(void *arg);