diff --git a/src/iperf_api.c b/src/iperf_api.c
index 7fb741e..4c73e83 100644
--- a/src/iperf_api.c
+++ b/src/iperf_api.c
@@ -2888,7 +2888,7 @@
 	i_errno = IENEWTEST;
 	return NULL;
     }
-    memset(test->bitrate_limit_intervals_traffic_bytes, 0, sizeof(sizeof(iperf_size_t) * MAX_INTERVAL));
+    memset(test->bitrate_limit_intervals_traffic_bytes, 0, sizeof(iperf_size_t) * MAX_INTERVAL);
 
     /* By default all output goes to stdout */
     test->outfile = stdout;