diff --git a/include/sys/resource.h b/include/sys/resource.h
index c55d4e63bd..9d604dfe3e 100644
--- a/include/sys/resource.h
+++ b/include/sys/resource.h
@@ -2,6 +2,116 @@
 #include <resource/sys/resource.h>
 
 #ifndef _ISOMAC
+# include <time.h>
+# include <string.h>
+
+/* Internal version of rusage with a 64-bit time_t. */
+#if __TIMESIZE == 64
+# define __rusage64 rusage
+#else
+struct __rusage64
+  {
+    struct __timeval64 ru_utime;
+    struct __timeval64 ru_stime;
+    __extension__ union
+      {
+	long int ru_maxrss;
+	__syscall_slong_t __ru_maxrss_word;
+      };
+    __extension__ union
+      {
+	long int ru_ixrss;
+	__syscall_slong_t __ru_ixrss_word;
+      };
+    __extension__ union
+      {
+	long int ru_idrss;
+	__syscall_slong_t __ru_idrss_word;
+      };
+    __extension__ union
+      {
+	long int ru_isrss;
+	 __syscall_slong_t __ru_isrss_word;
+      };
+    __extension__ union
+      {
+	long int ru_minflt;
+	__syscall_slong_t __ru_minflt_word;
+      };
+    __extension__ union
+      {
+	long int ru_majflt;
+	__syscall_slong_t __ru_majflt_word;
+      };
+    __extension__ union
+      {
+	long int ru_nswap;
+	__syscall_slong_t __ru_nswap_word;
+      };
+    __extension__ union
+      {
+	long int ru_inblock;
+	__syscall_slong_t __ru_inblock_word;
+      };
+    __extension__ union
+      {
+	long int ru_oublock;
+	__syscall_slong_t __ru_oublock_word;
+      };
+    __extension__ union
+      {
+	long int ru_msgsnd;
+	__syscall_slong_t __ru_msgsnd_word;
+      };
+    __extension__ union
+      {
+	long int ru_msgrcv;
+	__syscall_slong_t __ru_msgrcv_word;
+      };
+    __extension__ union
+      {
+	long int ru_nsignals;
+	__syscall_slong_t __ru_nsignals_word;
+      };
+    __extension__ union
+      {
+	long int ru_nvcsw;
+	__syscall_slong_t __ru_nvcsw_word;
+      };
+    __extension__ union
+      {
+	long int ru_nivcsw;
+	__syscall_slong_t __ru_nivcsw_word;
+      };
+  };
+#endif
+
+static inline void
+rusage64_to_rusage (const struct __rusage64 *restrict r64,
+                    struct rusage *restrict r)
+{
+  /* Make sure the entire output structure is cleared, including
+     padding and reserved fields.  */
+  memset (r, 0, sizeof *r);
+
+  r->ru_utime    = valid_timeval64_to_timeval (r64->ru_utime);
+  r->ru_stime    = valid_timeval64_to_timeval (r64->ru_stime);
+  r->ru_maxrss   = r64->ru_maxrss;
+  r->ru_ixrss    = r64->ru_ixrss;
+  r->ru_idrss    = r64->ru_idrss;
+  r->ru_isrss    = r64->ru_isrss;
+  r->ru_minflt   = r64->ru_minflt;
+  r->ru_majflt   = r64->ru_majflt;
+  r->ru_nswap    = r64->ru_nswap;
+  r->ru_inblock  = r64->ru_inblock;
+  r->ru_oublock  = r64->ru_oublock;
+  r->ru_msgsnd   = r64->ru_msgsnd;
+  r->ru_msgrcv   = r64->ru_msgrcv;
+  r->ru_nsignals = r64->ru_nsignals;
+  r->ru_nvcsw    = r64->ru_nvcsw;
+  r->ru_nivcsw   = r64->ru_nivcsw;
+}
+
 /* Prototypes repeated instead of using __typeof because
    sys/resource.h is included in C++ tests, and declaring functions
    with __typeof and __THROW doesn't work for C++.  */