diff --git a/src/node.cc b/src/node.cc
index 65f6fde74c..c7b17d4dfc 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -301,8 +301,10 @@ static inline const char *errno_string(int errorno) {
 
 #ifdef EAGAIN
   ERRNO_CASE(EAGAIN);
-#else
-# ifdef EWOULDBLOCK
+#endif
+
+#ifdef EWOULDBLOCK
+# if EAGAIN != EWOULDBLOCK
   ERRNO_CASE(EWOULDBLOCK);
 # endif
 #endif