diff --git a/src/xrt/auxiliary/gstreamer/gst_sink.c b/src/xrt/auxiliary/gstreamer/gst_sink.c
index fda3da8ff..2cf0e297d 100644
--- a/src/xrt/auxiliary/gstreamer/gst_sink.c
+++ b/src/xrt/auxiliary/gstreamer/gst_sink.c
@@ -48,7 +48,7 @@ gst_fmt_from_xf_format(enum xrt_format format_in)
 	case XRT_FORMAT_R8G8B8X8: return GST_VIDEO_FORMAT_RGBx;
 	case XRT_FORMAT_YUYV422: return GST_VIDEO_FORMAT_YUY2;
 	case XRT_FORMAT_L8: return GST_VIDEO_FORMAT_GRAY8;
-	default: assert(false);
+	default: assert(false); return GST_VIDEO_FORMAT_UNKNOWN;
 	}
 }
 
diff --git a/src/xrt/auxiliary/vk/vk_compositor_flags.c b/src/xrt/auxiliary/vk/vk_compositor_flags.c
index 647104411..b7d6dcde0 100644
--- a/src/xrt/auxiliary/vk/vk_compositor_flags.c
+++ b/src/xrt/auxiliary/vk/vk_compositor_flags.c
@@ -113,6 +113,7 @@ vk_csci_get_barrier_optimal_layout(VkFormat format)
 		return VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
 	default: //
 		assert(false && !"Format not supported!");
+		return VK_IMAGE_LAYOUT_UNDEFINED;
 	}
 }
 
@@ -142,6 +143,7 @@ vk_csci_get_barrier_aspect_mask(VkFormat format)
 		return VK_IMAGE_ASPECT_COLOR_BIT;
 	default: //
 		assert(false && !"Format not supported!");
+		return 0;
 	}
 }