diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c
index f4820fd3dc13ebe7f23547ee039f049117064b89..c0364314877ec6503e410b3e8dc01472c3404849 100644
--- a/drivers/i2c/busses/i2c-ismt.c
+++ b/drivers/i2c/busses/i2c-ismt.c
@@ -145,8 +145,8 @@
 #define ISMT_SPGT_SPD_MASK	0xc0000000	/* SMBus Speed mask */
 #define ISMT_SPGT_SPD_80K	0x00		/* 80 kHz */
 #define ISMT_SPGT_SPD_100K	(0x1 << 30)	/* 100 kHz */
-#define ISMT_SPGT_SPD_400K	(0x2 << 30)	/* 400 kHz */
-#define ISMT_SPGT_SPD_1M	(0x3 << 30)	/* 1 MHz */
+#define ISMT_SPGT_SPD_400K	(0x2U << 30)	/* 400 kHz */
+#define ISMT_SPGT_SPD_1M	(0x3U << 30)	/* 1 MHz */
 
 
 /* MSI Control Register (MSICTL) bit definitions */