diff --git a/src/unix/getaddrinfo.c b/src/unix/getaddrinfo.c
index 5718af64..d09bfcdc 100644
--- a/src/unix/getaddrinfo.c
+++ b/src/unix/getaddrinfo.c
@@ -18,6 +18,13 @@
  * IN THE SOFTWARE.
  */
 
+/* Expose glibc-specific EAI_* error codes. Needs to be defined before we
+ * include any headers.
+ */
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
 #include "uv.h"
 #include "internal.h"
 
diff --git a/src/uv-common.c b/src/uv-common.c
index aaee9305..9a597d38 100644
--- a/src/uv-common.c
+++ b/src/uv-common.c
@@ -19,13 +19,6 @@
  * IN THE SOFTWARE.
  */
 
-/* Expose glibc-specific EAI_* error codes. Needs to be defined before we
- * include any headers.
- */
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 #include "uv.h"
 #include "uv-common.h"