diff --git a/util.c b/util.c
index d745c58..b66f7e1 100644
--- a/util.c
+++ b/util.c
@@ -63,14 +63,9 @@ uint64_t mstime(void)
     return mst;
 }
 
-uint64_t receiveclock_ns_elapsed(uint64_t t1, uint64_t t2)
+int64_t receiveclock_ns_elapsed(uint64_t t1, uint64_t t2)
 {
-    if (t2 < t1) {
-        // wrapped.
-        return (~(t1 - t2) + 1) * 1000U / 12U;
-    } else {
-        return (t2 - t1) * 1000U / 12U;
-    }
+    return (t2 - t1) * 1000U / 12U;
 }
 
 void normalize_timespec(struct timespec *ts)
diff --git a/util.h b/util.h
index 3cb022a..41ccbb1 100644
--- a/util.h
+++ b/util.h
@@ -26,10 +26,9 @@
 uint64_t mstime(void);
 
 /* Returns the time elapsed, in nanoseconds, from t1 to t2,
- * where t1 and t2 are 12MHz counters,
- * accounting for wrapping.
+ * where t1 and t2 are 12MHz counters.
  */
-uint64_t receiveclock_ns_elapsed(uint64_t t1, uint64_t t2);
+int64_t receiveclock_ns_elapsed(uint64_t t1, uint64_t t2);
 
 /* Normalize the value in ts so that ts->nsec lies in
  * [0,999999999]