diff --git a/src/renderer/generic.zig b/src/renderer/generic.zig
index 83417429e..f57339893 100644
--- a/src/renderer/generic.zig
+++ b/src/renderer/generic.zig
@@ -1226,6 +1226,10 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                 // kitty state on every frame because any cell change can move
                 // an image.
                 if (self.images.kittyRequiresUpdate(state.terminal)) {
+                    // We need to grab the draw mutex since this updates
+                    // our image state that drawFrame uses.
+                    self.draw_mutex.lock();
+                    defer self.draw_mutex.unlock();
                     self.images.kittyUpdate(
                         self.alloc,
                         state.terminal,
diff --git a/src/renderer/image.zig b/src/renderer/image.zig
index 85f3a01ed..c43d27981 100644
--- a/src/renderer/image.zig
+++ b/src/renderer/image.zig
@@ -844,7 +844,7 @@ pub const Image = union(enum) {
     /// Converts the image data to a format that can be uploaded to the GPU.
     /// If the data is already in a format that can be uploaded, this is a
     /// no-op.
-    pub fn convert(self: *Image, alloc: Allocator) wuffs.Error!void {
+    fn convert(self: *Image, alloc: Allocator) wuffs.Error!void {
         const p = self.getPendingPointer().?;
         // As things stand, we currently convert all images to RGBA before
         // uploading to the GPU. This just makes things easier. In the future
@@ -867,7 +867,7 @@ pub const Image = union(enum) {
 
     /// Prepare the pending image data for upload to the GPU.
     /// This doesn't need GPU access so is safe to call any time.
-    pub fn prepForUpload(self: *Image, alloc: Allocator) wuffs.Error!void {
+    fn prepForUpload(self: *Image, alloc: Allocator) wuffs.Error!void {
         assert(self.isPending());
         try self.convert(alloc);
     }