diff --git a/device/camera/camera_output.c b/device/camera/camera_output.c
index 5ef5f91..f579098 100644
--- a/device/camera/camera_output.c
+++ b/device/camera/camera_output.c
@@ -16,7 +16,7 @@
 
 static bool camera_output_matches_capture(buffer_list_t *capture, unsigned target_height, unsigned format)
 {
-  if (target_height && abs(capture->fmt.height - target_height) > MATCH_ALIGN_SIZE) {
+  if (target_height && abs((int)capture->fmt.height - (int)target_height) > MATCH_ALIGN_SIZE) {
     return false;
   }
 
diff --git a/device/device.c b/device/device.c
index 7151ac8..36826f9 100644
--- a/device/device.c
+++ b/device/device.c
@@ -56,7 +56,7 @@ buffer_list_t *device_open_buffer_list2(device_t *dev, const char *path, bool do
 {
   char name[64];
   int index = 0;
-  buffer_list_t *buf_list;
+  buffer_list_t *buf_list = NULL;
 
   if (!dev) {
     return NULL;
diff --git a/device/libcamera/fake_camera.c b/device/libcamera/fake_camera.c
index 9b1ef32..8026be7 100644
--- a/device/libcamera/fake_camera.c
+++ b/device/libcamera/fake_camera.c
@@ -26,7 +26,7 @@ void fake_camera_sensor(struct media_v2_topology *topology)
   }
 
   char source[256];
-  sprintf(source, fake_camera);
+  strcpy(source, fake_camera);
 
   char *target = strstr(source, "=");
   if (!target) {