diff --git a/webui.py b/webui.py
index 76edacbc5..e5a21b2f8 100644
--- a/webui.py
+++ b/webui.py
@@ -37,6 +37,7 @@ from contextlib import nullcontext
 import signal
 import tqdm
 import re
+import threading
 
 import k_diffusion.sampling
 from ldm.util import instantiate_from_config
@@ -75,6 +76,7 @@ cpu = torch.device("cpu")
 gpu = torch.device("cuda")
 device = gpu if torch.cuda.is_available() else cpu
 batch_cond_uncond = not (cmd_opts.lowvram or cmd_opts.medvram)
+queue_lock = threading.Lock()
 
 if not cmd_opts.share:
     # fix gradio phoning home
@@ -643,10 +645,20 @@ def resize_image(resize_mode, im, width, height):
     return res
 
 
+def wrap_gradio_gpu_call(func):
+    def f(*args, **kwargs):
+        with queue_lock:
+            res = func(*args, **kwargs)
+
+        return res
+
+    return f
+
+
 def wrap_gradio_call(func):
-    def f(*p1, **p2):
+    def f(*args, **kwargs):
         t = time.perf_counter()
-        res = list(func(*p1, **p2))
+        res = list(func(*args, **kwargs))
         elapsed = time.perf_counter() - t
 
         # last item is always HTML
@@ -1259,7 +1271,7 @@ with gr.Blocks(analytics_enabled=False) as txt2img_interface:
                 html_info = gr.HTML()
 
         txt2img_args = dict(
-            fn=wrap_gradio_call(txt2img),
+            fn=wrap_gradio_gpu_call(txt2img),
             inputs=[
                 prompt,
                 negative_prompt,
@@ -1657,7 +1669,7 @@ with gr.Blocks(analytics_enabled=False) as img2img_interface:
         )
 
         img2img_args = dict(
-            fn=wrap_gradio_call(img2img),
+            fn=wrap_gradio_gpu_call(img2img),
             inputs=[
                 prompt,
                 init_img,
@@ -1736,7 +1748,7 @@ def run_extras(image, GFPGAN_strength, RealESRGAN_upscaling, RealESRGAN_model_in
 
 
 extras_interface = gr.Interface(
-    wrap_gradio_call(run_extras),
+    wrap_gradio_gpu_call(run_extras),
     inputs=[
         gr.Image(label="Source", source="upload", interactive=True, type="pil"),
         gr.Slider(minimum=0.0, maximum=1.0, step=0.001, label="GFPGAN strength", value=1, interactive=have_gfpgan),
@@ -1904,6 +1916,5 @@ def inject_gradio_html(javascript):
 
 inject_gradio_html(javascript)
 
-demo.queue(concurrency_count=1)
 demo.launch(share=cmd_opts.share)