diff --git a/tc/tc_core.c b/tc/tc_core.c
index 55586741..07cf2fa9 100644
--- a/tc/tc_core.c
+++ b/tc/tc_core.c
@@ -50,6 +50,8 @@ int tc_calc_rtable(unsigned bps, __u32 *rtab, int cell_log, unsigned mtu,
 		   unsigned mpu)
 {
 	int i;
+	unsigned overhead = (mpu >> 8) & 0xFF;
+	mpu = mpu & 0xFF;
 
 	if (mtu == 0)
 		mtu = 2047;
@@ -61,6 +63,8 @@ int tc_calc_rtable(unsigned bps, __u32 *rtab, int cell_log, unsigned mtu,
 	}
 	for (i=0; i<256; i++) {
 		unsigned sz = (i<<cell_log);
+		if (overhead)
+			sz += overhead;
 		if (sz < mpu)
 			sz = mpu;
 		rtab[i] = tc_core_usec2tick(1000000*((double)sz/bps));