diff --git a/headers/private/kernel/arch/arm/arch_atomic.h b/headers/private/kernel/arch/arm/arch_atomic.h
index 50b4bb791d..1c5b5e3ff3 100644
--- a/headers/private/kernel/arch/arm/arch_atomic.h
+++ b/headers/private/kernel/arch/arm/arch_atomic.h
@@ -9,12 +9,20 @@
 #define _KERNEL_ARCH_ARM_ATOMIC_H
 
 
-#if __ARM_ARCH__ <= 6
+#if __ARM_ARCH__ <= 5
+#define isb() __asm__ __volatile__("" : : : "memory")
+#define dsb() __asm__ __volatile__("mcr p15, 0, %0, c7, c10, 4" \
+    : : "r" (0) : "memory")
+#define dmb() __asm__ __volatile__("" : : : "memory")
+#elif __ARM_ARCH__ == 6
+#define isb() __asm__ __volatile__("mcr p15, 0, %0, c7, c5, 4" \
+	: : "r" (0) : "memory")
 #define dsb() __asm__ __volatile__("mcr p15, 0, %0, c7, c10, 4" \
     : : "r" (0) : "memory")
 #define dmb() __asm__ __volatile__("mcr p15, 0, %0, c7, c10, 4" \
     : : "r" (0) : "memory")
-#else
+#else /* ARMv7+ */
+#define isb() __asm__ __volatile__("isb" : : : "memory")
 #define dsb() __asm__ __volatile__("dsb" : : : "memory")
 #define dmb() __asm__ __volatile__("dmb" : : : "memory")
 #endif
diff --git a/src/system/libroot/os/arch/arm/thread.c b/src/system/libroot/os/arch/arm/thread.c
index cb233d4147..e922970bca 100644
--- a/src/system/libroot/os/arch/arm/thread.c
+++ b/src/system/libroot/os/arch/arm/thread.c
@@ -27,5 +27,5 @@ find_thread(const char *name)
 void
 __sync_synchronize(void)
 {
-	dsb();
+	dmb();
 }