diff --git a/include/types/wlr_output.h b/include/types/wlr_output.h
index e754053f..22a5c463 100644
--- a/include/types/wlr_output.h
+++ b/include/types/wlr_output.h
@@ -12,7 +12,7 @@ bool output_pick_format(struct wlr_output *output,
 	struct wlr_drm_format *format, uint32_t fmt);
 void output_clear_back_buffer(struct wlr_output *output);
 bool output_ensure_buffer(struct wlr_output *output,
-	const struct wlr_output_state *state, bool *new_back_buffer);
+	struct wlr_output_state *state, bool *new_back_buffer);
 
 bool output_cursor_set_texture(struct wlr_output_cursor *cursor,
 	struct wlr_texture *texture, bool own_texture, float scale,
diff --git a/types/output/output.c b/types/output/output.c
index 6b332e1c..c879b997 100644
--- a/types/output/output.c
+++ b/types/output/output.c
@@ -684,14 +684,10 @@ bool wlr_output_test_state(struct wlr_output *output,
 	if (!output_ensure_buffer(output, &copy, &new_back_buffer)) {
 		return false;
 	}
-	if (new_back_buffer) {
-		assert((copy.committed & WLR_OUTPUT_STATE_BUFFER) == 0);
-		copy.committed |= WLR_OUTPUT_STATE_BUFFER;
-		copy.buffer = output->back_buffer;
-	}
 
 	bool success = output->impl->test(output, &copy);
 	if (new_back_buffer) {
+		wlr_buffer_unlock(copy.buffer);
 		output_clear_back_buffer(output);
 	}
 	return success;
@@ -728,8 +724,6 @@ bool wlr_output_commit_state(struct wlr_output *output,
 		return false;
 	}
 	if (new_back_buffer) {
-		assert((pending.committed & WLR_OUTPUT_STATE_BUFFER) == 0);
-		wlr_output_state_set_buffer(&pending, output->back_buffer);
 		output_clear_back_buffer(output);
 	}
 
diff --git a/types/output/render.c b/types/output/render.c
index 9637ae47..193c5a6f 100644
--- a/types/output/render.c
+++ b/types/output/render.c
@@ -116,8 +116,7 @@ static bool output_attach_empty_back_buffer(struct wlr_output *output,
 // This function may attach a new, empty back buffer if necessary.
 // If so, the new_back_buffer out parameter will be set to true.
 bool output_ensure_buffer(struct wlr_output *output,
-		const struct wlr_output_state *state,
-		bool *new_back_buffer) {
+		struct wlr_output_state *state, bool *new_back_buffer) {
 	assert(*new_back_buffer == false);
 
 	// If we already have a buffer, we don't need to allocate a new one
@@ -164,6 +163,7 @@ bool output_ensure_buffer(struct wlr_output *output,
 	}
 
 	*new_back_buffer = true;
+	wlr_output_state_set_buffer(state, output->back_buffer);
 	return true;
 }