diff --git a/armsrc/ticks.c b/armsrc/ticks.c
index 3c485e072..f084e3364 100644
--- a/armsrc/ticks.c
+++ b/armsrc/ticks.c
@@ -91,7 +91,7 @@ void StartCountUS(void) {
 uint32_t RAMFUNC GetCountUS(void){
 	//return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV / 15) * 10);
 	//  By suggestion from PwPiwi, http://www.proxmark.org/forum/viewtopic.php?pid=17548#p17548
-	return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV * 2) / 3); 
+	return ((uint32_t)AT91C_BASE_TC1->TC_CV) * 0x8000 + (((uint32_t)AT91C_BASE_TC0->TC_CV) * 2) / 3;
 }
 
 //  -------------------------------------------------------------------------