diff --git a/arch/arm/mach-omap2/prm3xxx.c b/arch/arm/mach-omap2/prm3xxx.c
index 62680aad2126..718981bb80cd 100644
--- a/arch/arm/mach-omap2/prm3xxx.c
+++ b/arch/arm/mach-omap2/prm3xxx.c
@@ -319,6 +319,9 @@ void __init omap3_prm_init_pm(bool has_uart4, bool has_iva)
 	if (has_uart4) {
 		en_uart4_mask = OMAP3630_EN_UART4_MASK;
 		grpsel_uart4_mask = OMAP3630_GRPSEL_UART4_MASK;
+	} else {
+		en_uart4_mask = 0;
+		grpsel_uart4_mask = 0;
 	}
 
 	/* Enable wakeups in PER */