diff --git a/litex/soc/software/libbase/memtest.c b/litex/soc/software/libbase/memtest.c
index 625b46429..2c51580b2 100644
--- a/litex/soc/software/libbase/memtest.c
+++ b/litex/soc/software/libbase/memtest.c
@@ -179,7 +179,7 @@ void memspeed(unsigned int *addr, unsigned long size, bool read_only)
 {
 	volatile unsigned long *array = (unsigned long *)addr;
 	int i;
-	unsigned int start, end;
+	uint32_t start, end;
 	unsigned long write_speed = 0;
 	unsigned long read_speed;
 	__attribute__((unused)) unsigned long data;
@@ -202,8 +202,10 @@ void memspeed(unsigned int *addr, unsigned long size, bool read_only)
 		}
 		timer0_update_value_write(1);
 		end = timer0_value_read();
-		write_speed = (size*(CONFIG_CLOCK_FREQUENCY/1000000))/(start - end);
-		printf("  Write: %ldMiB/s\n", write_speed);
+		uint64_t numerator = ((uint64_t)size)*((uint64_t)CONFIG_CLOCK_FREQUENCY);
+		uint64_t denominator = ((uint64_t)start - (uint64_t)end);
+		write_speed = numerator/denominator;
+		printf("  Write speed: %lub/s\n", write_speed);
 	}
 
 	/* flush CPU and L2 caches */
@@ -221,8 +223,10 @@ void memspeed(unsigned int *addr, unsigned long size, bool read_only)
 	}
 	timer0_update_value_write(1);
 	end = timer0_value_read();
-	read_speed = (size*(CONFIG_CLOCK_FREQUENCY/1000000))/(start - end);
-	printf("  Read:  %ldMiB/s\n", read_speed);
+	uint64_t numerator = ((uint64_t)size)*((uint64_t)CONFIG_CLOCK_FREQUENCY);
+	uint64_t denominator = ((uint64_t)start - (uint64_t)end);
+	read_speed = numerator/denominator;
+	printf("  Read speed:  %lub/s\n", read_speed);
 }
 
 int memtest(unsigned int *addr, unsigned long maxsize)