diff --git a/girepository.c b/girepository.c
index 97074a8ce..bb91977ec 100644
--- a/girepository.c
+++ b/girepository.c
@@ -28,6 +28,7 @@
 #include <stdlib.h>
 
 #ifdef HAVE_GETAUXVAL
+#include <unistd.h>
 #include <sys/auxv.h>
 #endif