diff --git a/core/include/attributes.h b/core/include/attributes.h
index e0ae7fbd7a..b1efec6dbf 100644
--- a/core/include/attributes.h
+++ b/core/include/attributes.h
@@ -56,6 +56,18 @@
 #define PURE
 #endif
 
+/**
+ * @def       UNREACHABLE()
+ * @brief     Tell the compiler that this line of code cannot be reached.
+ * @details   Most useful in junction with #NORETURN.
+ *            Use this if the compiler cannot tell that e.g.
+ *            an assembler instruction causes a longjmp, or a write causes a reboot.
+ */
+#if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ >= 5)
+#define UNREACHABLE() __builtin_unreachable()
+#else
+#define UNREACHABLE() do { /* nothing */ } while (1)
+#endif
+
 #endif /* ATTRIBUTES_H_ */
 /** @} */
-
diff --git a/cpu/arm_common/crash.c b/cpu/arm_common/crash.c
index 366e3f8393..70671cd297 100644
--- a/cpu/arm_common/crash.c
+++ b/cpu/arm_common/crash.c
@@ -63,11 +63,5 @@ NORETURN void core_panic(int crash_code, const char *message)
 
     /* tell the compiler that we won't return from this function
        (even if we actually won't even get here...) */
-#if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ >= 5)
-    __builtin_unreachable();
-#else
-    while (1) {
-        /* do nothing, but do it often */
-    }
-#endif
+    UNREACHABLE();
 }
diff --git a/cpu/lpc1768/crash.c b/cpu/lpc1768/crash.c
index 9c26664b45..9a449d9e97 100644
--- a/cpu/lpc1768/crash.c
+++ b/cpu/lpc1768/crash.c
@@ -64,11 +64,5 @@ NORETURN void core_panic(int crash_code, const char *message)
 
     /* tell the compiler that we won't return from this function
        (even if we actually won't even get here...) */
-#if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ >= 5)
-    __builtin_unreachable();
-#else
-    while (1) {
-        /* do nothing, but do it often */
-    }
-#endif
+    UNREACHABLE();
 }
diff --git a/cpu/msp430-common/crash.c b/cpu/msp430-common/crash.c
index 365dd91ad6..3a45e62331 100644
--- a/cpu/msp430-common/crash.c
+++ b/cpu/msp430-common/crash.c
@@ -63,11 +63,5 @@ NORETURN void core_panic(int crash_code, const char *message)
 
     /* tell the compiler that we won't return from this function
        (even if we actually won't even get here...) */
-#if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ >= 5)
-    __builtin_unreachable();
-#else
-    while (1) {
-        /* do nothing, but do it often */
-    }
-#endif
+    UNREACHABLE();
 }
diff --git a/cpu/native/crash.c b/cpu/native/crash.c
index dfcd6be18a..b6f0532352 100644
--- a/cpu/native/crash.c
+++ b/cpu/native/crash.c
@@ -60,11 +60,5 @@ NORETURN void core_panic(int crash_code, const char *message)
 
     /* tell the compiler that we won't return from this function
        (even if we actually won't even get here...) */
-#if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ >= 5)
-    __builtin_unreachable();
-#else
-    while (1) {
-        /* do nothing, but do it often */
-    }
-#endif
+    UNREACHABLE();
 }