--- src/gdbm.h.in.orig	2021-08-21 13:03:40.000000000 -0700
+++ src/gdbm.h.in	2021-08-21 13:08:48.000000000 -0700
@@ -31,6 +31,13 @@
 
 # include <stdio.h>
 
+#if defined(__APPLE__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1050
+#ifndef _OFF_T
+#define _OFF_T
+typedef __darwin_off_t      off_t;
+#endif
+#endif
+
 /* GDBM C++ support */
 # if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
