diff --git a/portable/ThirdParty/GCC/Posix/port.c b/portable/ThirdParty/GCC/Posix/port.c
index 05f08cf7c..0b18da4df 100644
--- a/portable/ThirdParty/GCC/Posix/port.c
+++ b/portable/ThirdParty/GCC/Posix/port.c
@@ -180,7 +180,7 @@ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
     thread->xDying = pdFALSE;
 
     /* Ensure ulStackSize is at least PTHREAD_STACK_MIN */
-    ulStackSize = (ulStackSize < PTHREAD_STACK_MIN) ? PTHREAD_STACK_MIN : ulStackSize;
+    ulStackSize = (ulStackSize < ( size_t ) ( PTHREAD_STACK_MIN ) ) ? ( size_t ) ( PTHREAD_STACK_MIN ) : ulStackSize;
 
     pthread_attr_init( &xThreadAttributes );
     iRet = pthread_attr_setstacksize( &xThreadAttributes, ulStackSize );