diff --git a/arch/arm/src/sam3u/sam3u_lowputc.c b/arch/arm/src/sam3u/sam3u_lowputc.c
index a5cf813628b..a0e0f992658 100755
--- a/arch/arm/src/sam3u/sam3u_lowputc.c
+++ b/arch/arm/src/sam3u/sam3u_lowputc.c
@@ -242,7 +242,7 @@ void sam3u_lowsetup(void)
 
   /* Enable clocking for all selected UART/USARTs */
 
-  regval = getreg32(SAM3U_PMC_PCER);
+  regval = 0;
 #ifdef CONFIG_SAM3U_UART
   regval |= (1 << SAM3U_PID_UART);
 #endif