diff --git a/libcpu/arm/cortex-r4/start_gcc.S b/libcpu/arm/cortex-r4/start_gcc.S
index 3d679d0a22c719a7a5a5676ff3a30fd832801e33..1ed1e396aff26bb942cb8258038da415125ee970 100644
--- a/libcpu/arm/cortex-r4/start_gcc.S
+++ b/libcpu/arm/cortex-r4/start_gcc.S
@@ -30,7 +30,7 @@
 
 stack_start:
 .rept (UND_Stack_Size + SVC_Stack_Size + ABT_Stack_Size + FIQ_Stack_Size + IRQ_Stack_Size)
-.long 0
+.byte 0
 .endr
 stack_top: