diff --git a/src/ibex_system.c b/src/ibex_system.c
index 86014b3..c05f087 100644
--- a/src/ibex_system.c
+++ b/src/ibex_system.c
@@ -29,8 +29,7 @@ uint64_t __read_mcycle(void) {
     __csrr("mcycle", mcycle);
     __csrr("mcycleh", mcycleh);
 
-    uint64_t ret = mcycleh << 31;
-    ret <<= 1;
+    uint64_t ret = (uint64_t)mcycleh << 32;
     ret |= mcycle;
 
     return ret;