diff --git a/src/bin/gdb/readline/support/wcwidth.c b/src/bin/gdb/readline/support/wcwidth.c
index ace9a3ab92..29f5593e8f 100644
--- a/src/bin/gdb/readline/support/wcwidth.c
+++ b/src/bin/gdb/readline/support/wcwidth.c
@@ -6,6 +6,7 @@
  * Markus Kuhn -- 2001-09-08 -- public domain
  */
 
+#include <sys/types.h>
 #include <wchar.h>
 
 struct interval {