diff --git a/test/log.c b/test/log.c
index b9dfffca..908af7e4 100644
--- a/test/log.c
+++ b/test/log.c
@@ -45,7 +45,7 @@ static void close_restricted(int fd, void *data)
 	close(fd);
 }
 
-const struct libinput_interface simple_interface = {
+static const struct libinput_interface simple_interface = {
 	.open_restricted = open_restricted,
 	.close_restricted = close_restricted,
 };
diff --git a/test/misc.c b/test/misc.c
index ade053f9..dec4ee4c 100644
--- a/test/misc.c
+++ b/test/misc.c
@@ -43,7 +43,7 @@ static void close_restricted(int fd, void *data)
 	close(fd);
 }
 
-const struct libinput_interface simple_interface = {
+static const struct libinput_interface simple_interface = {
 	.open_restricted = open_restricted,
 	.close_restricted = close_restricted,
 };
diff --git a/test/path.c b/test/path.c
index 729ad868..21b5fa08 100644
--- a/test/path.c
+++ b/test/path.c
@@ -49,7 +49,7 @@ static void close_restricted(int fd, void *data)
 	close(fd);
 }
 
-const struct libinput_interface simple_interface = {
+static const struct libinput_interface simple_interface = {
 	.open_restricted = open_restricted,
 	.close_restricted = close_restricted,
 };
diff --git a/test/udev.c b/test/udev.c
index 9296e94c..7c294c59 100644
--- a/test/udev.c
+++ b/test/udev.c
@@ -44,7 +44,7 @@ static void close_restricted(int fd, void *data)
 	close(fd);
 }
 
-const struct libinput_interface simple_interface = {
+static const struct libinput_interface simple_interface = {
 	.open_restricted = open_restricted,
 	.close_restricted = close_restricted,
 };