diff --git a/reactos/hal/halx86/include/hal.h b/reactos/hal/halx86/include/hal.h
index 18c91959d04..bbda83fa7fe 100644
--- a/reactos/hal/halx86/include/hal.h
+++ b/reactos/hal/halx86/include/hal.h
@@ -419,7 +419,7 @@ HalQueryDisplayOwnership();
 static inline BYTE Ki386ReadFsByte(ULONG offset)
 {
    BYTE b;
-   __asm__ __volatile__("movb %%fs:(%1),%0":"=r" (b):"r" (offset));
+   __asm__ __volatile__("movb %%fs:(%1),%0":"=q" (b):"r" (offset));
    return b;
 }