diff --git a/numpy/core/src/multiarray/convert.c b/numpy/core/src/multiarray/convert.c
index 29a2bb0e8..77aa72033 100644
--- a/numpy/core/src/multiarray/convert.c
+++ b/numpy/core/src/multiarray/convert.c
@@ -20,8 +20,8 @@
 
 #include "convert.h"
 
-int
-fallocate(int fd, int mode, off_t offset, off_t len);
+#define _GNU_SOURCE             /* See feature_test_macros(7) */
+#include <fcntl.h>
 
 /*
  * allocate nbytes of diskspace for file fp