diff --git a/firmware/target/arm/as3525/system-as3525.c b/firmware/target/arm/as3525/system-as3525.c
index 90535fc170..b1b1967936 100644
--- a/firmware/target/arm/as3525/system-as3525.c
+++ b/firmware/target/arm/as3525/system-as3525.c
@@ -441,13 +441,13 @@ void set_cpu_frequency(long frequency)
         /* Change PCLK while FCLK is low, so it doesn't go too high */
         CGU_PERI = (CGU_PERI & ~(0x1F << 2)) | (AS3525_PCLK_DIV0 << 2);
 
-        delay = 40; while(delay--) ;
+        delay = 40; while(delay--) asm("nop");
 
         CGU_PROC = ((AS3525_FCLK_POSTDIV << 4) |
                     (AS3525_FCLK_PREDIV  << 2) |
                     AS3525_FCLK_SEL);
 
-        delay = 40; while(delay--) ;
+        delay = 40; while(delay--) asm("nop");
 
     }
     else
@@ -458,11 +458,11 @@ void set_cpu_frequency(long frequency)
                     (AS3525_FCLK_PREDIV  << 2) |
                     AS3525_FCLK_SEL);
 
-        delay = 40; while(delay--) ;
+        delay = 40; while(delay--) asm("nop");
 
         /* Change PCLK after FCLK is low, so it doesn't go too high */
         CGU_PERI = (CGU_PERI & ~(0x1F << 2)) | (AS3525_PCLK_DIV0_UNBOOSTED << 2);
-        delay = 40; while(delay--) ;
+        delay = 40; while(delay--) asm("nop");
     }
 
     cpu_frequency = frequency;