diff --git a/include/ck_cc.h b/include/ck_cc.h
index 5586cdc..4c35e19 100644
--- a/include/ck_cc.h
+++ b/include/ck_cc.h
@@ -77,4 +77,12 @@
 #define CK_CC_CACHELINE
 #endif
 
+#ifndef CK_CC_LIKELY
+#define CK_CC_LIKELY(x)
+#endif
+
+#ifndef CK_CC_UNLIKELY
+#define CK_CC_UNLIKELY(x)
+#endif
+
 #endif /* _CK_CC_H */
diff --git a/include/gcc/ck_cc.h b/include/gcc/ck_cc.h
index b4a0e2b..8feaaa5 100644
--- a/include/gcc/ck_cc.h
+++ b/include/gcc/ck_cc.h
@@ -75,6 +75,12 @@
 #pragma GCC poison malloc free
 #endif
 
+/*
+ * Branch execution hints.
+ */
+#define CK_CC_LIKELY(x) (__builtin_expect(!!(x), 1))
+#define CK_CC_UNLIKELY(x) (__builtin_expect(!!(x), 0))
+
 /*
  * Some compilers are overly strict regarding aliasing semantics.
  * Unfortunately, in many cases it makes more sense to pay aliasing