diff --git a/src/os/unix/ngx_linux_config.h b/src/os/unix/ngx_linux_config.h
index e4c5dd0..cfd9413 100644
--- a/src/os/unix/ngx_linux_config.h
+++ b/src/os/unix/ngx_linux_config.h
@@ -26,6 +26,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <netdb.h>
 
 
 typedef unsigned int   u_int;