diff --git a/libgomp/env.c b/libgomp/env.c
--- a/libgomp/env.c
+++ b/libgomp/env.c
@@ -54,6 +54,13 @@
 #include <errno.h>
 #include "thread-stacksize.h"
 
+#ifdef __APPLE__
+# include <crt_externs.h>
+# define environ (*_NSGetEnviron ())
+#else
+extern char **environ;
+#endif
+
 #ifndef HAVE_STRTOULL
 # define strtoull(ptr, eptr, base) strtoul (ptr, eptr, base)
 #endif
@@ -2033,7 +2040,6 @@ startswith (const char *str, const char 
 static void __attribute__((constructor))
 initialize_env (void)
 {
-  extern char **environ;
   char **env;
   int omp_var, dev_num = 0, dev_num_len = 0, i;
   bool ignore = false;