diff --git a/src/bpf_helpers.h b/src/bpf_helpers.h
index ae6c975..53ff81c 100644
--- a/src/bpf_helpers.h
+++ b/src/bpf_helpers.h
@@ -29,9 +29,10 @@
  */
 #define SEC(NAME) __attribute__((section(NAME), used))
 
-#ifndef __always_inline
+/* Avoid 'linux/stddef.h' definition of '__always_inline'. */
+#undef __always_inline
 #define __always_inline inline __attribute__((always_inline))
-#endif
+
 #ifndef __noinline
 #define __noinline __attribute__((noinline))
 #endif