diff --git a/fish/fish.c b/fish/fish.c
index 2411f7215..2022ee3ad 100644
--- a/fish/fish.c
+++ b/fish/fish.c
@@ -28,6 +28,7 @@
 #include <assert.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <locale.h>
 
 #ifdef HAVE_LIBREADLINE
 #include <readline/readline.h>
diff --git a/test-tool/test-tool.c b/test-tool/test-tool.c
index 78a608f90..0f5ebfc1d 100644
--- a/test-tool/test-tool.c
+++ b/test-tool/test-tool.c
@@ -29,6 +29,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <locale.h>
 
 #include <guestfs.h>