diff --git a/auto/os/conf b/auto/os/conf
index fe72016..6ad0e74 100644
--- a/auto/os/conf
+++ b/auto/os/conf
@@ -60,6 +60,15 @@
         CORE_SRCS="$UNIX_SRCS"
     ;;
 
+    GNU:*)
+        # GNU Hurd
+        have=NGX_GNU_HURD . auto/have_headers
+        CORE_INCS="$UNIX_INCS"
+        CORE_DEPS="$UNIX_DEPS $POSIX_DEPS"
+        CORE_SRCS="$UNIX_SRCS"
+        CC_AUX_FLAGS="$CC_AUX_FLAGS -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"
+    ;;
+
     *)
         CORE_INCS="$UNIX_INCS"
         CORE_DEPS="$UNIX_DEPS $POSIX_DEPS"
diff --git a/src/os/unix/ngx_posix_config.h b/src/os/unix/ngx_posix_config.h
index d725659..443c4b0 100644
--- a/src/os/unix/ngx_posix_config.h
+++ b/src/os/unix/ngx_posix_config.h
@@ -21,6 +21,14 @@
 #endif
 
 
+#if (NGX_GNU_HURD)
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE             /* accept4() */
+#endif
+#define _FILE_OFFSET_BITS       64
+#endif
+
+
 #ifdef __CYGWIN__
 #define timezonevar             /* timezone is variable */
 #define NGX_BROKEN_SCM_RIGHTS   1