diff --git a/arch/arm/src/lm3s/lm3s_syscontrol.c b/arch/arm/src/lm3s/lm3s_syscontrol.c
index f7a9528c1f0..bd67a6ae19d 100644
--- a/arch/arm/src/lm3s/lm3s_syscontrol.c
+++ b/arch/arm/src/lm3s/lm3s_syscontrol.c
@@ -110,7 +110,7 @@ static inline void lm3s_oscdelay(uint32_t rcc, uint32_t rcc2)
    * current clock rate is very slow.
    */
 
-  uint32_t delay   = FAST_OSCDELAY;
+  uint32_t delay = FAST_OSCDELAY;
 
   /* Are we currently using RCC2? */
 
@@ -150,7 +150,7 @@ static inline void lm3s_oscdelay(uint32_t rcc, uint32_t rcc2)
 
 static inline void lm3s_plllock(void)
 {
-  uint32_t delay;
+  volatile uint32_t delay;
 
   /* Loop until the lock is achieved or until a timeout occurs */