diff --git a/auto/os/conf b/auto/os/conf
index 5e658b5f3..fe720160a 100644
--- a/auto/os/conf
+++ b/auto/os/conf
@@ -48,6 +48,7 @@ case "$NGX_PLATFORM" in
         CORE_DEPS="$UNIX_DEPS $POSIX_DEPS"
         CORE_SRCS="$UNIX_SRCS"
         CC_AUX_FLAGS="$CC_AUX_FLAGS -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED=1"
+        CC_AUX_FLAGS="$CC_AUX_FLAGS -D_HPUX_ALT_XOPEN_SOCKET_API"
     ;;
 
     OSF1:*)
diff --git a/src/os/unix/ngx_posix_config.h b/src/os/unix/ngx_posix_config.h
index 4d432a7e3..4cf90cc98 100644
--- a/src/os/unix/ngx_posix_config.h
+++ b/src/os/unix/ngx_posix_config.h
@@ -12,6 +12,7 @@
 #if (NGX_HPUX)
 #define _XOPEN_SOURCE
 #define _XOPEN_SOURCE_EXTENDED  1
+#define _HPUX_ALT_XOPEN_SOCKET_API
 #endif