diff --git a/impeller/renderer/backend/gles/context_gles.cc b/impeller/renderer/backend/gles/context_gles.cc
index e6234c642038e..e86302daa930e 100644
--- a/impeller/renderer/backend/gles/context_gles.cc
+++ b/impeller/renderer/backend/gles/context_gles.cc
@@ -122,6 +122,15 @@ std::shared_ptr<CommandBuffer> ContextGLES::CreateCommandBuffer() const {
       new CommandBufferGLES(weak_from_this(), reactor_));
 }
 
+// |Context|
+bool ContextGLES::WaitUntilCommandsCompleted() {
+  const auto result = reactor_->React();
+  if (result) {
+    reactor_->GetProcTable().Finish();
+  }
+  return result;
+}
+
 // |Context|
 std::shared_ptr<WorkQueue> ContextGLES::GetWorkQueue() const {
   return work_queue_;
diff --git a/impeller/renderer/backend/gles/context_gles.h b/impeller/renderer/backend/gles/context_gles.h
index 138843a7fb7a3..7dcfeaf8f249f 100644
--- a/impeller/renderer/backend/gles/context_gles.h
+++ b/impeller/renderer/backend/gles/context_gles.h
@@ -73,6 +73,9 @@ class ContextGLES final : public Context,
   // |Context|
   bool SupportsOffscreenMSAA() const override;
 
+  // |Context|
+  bool WaitUntilCommandsCompleted() override;
+
   FML_DISALLOW_COPY_AND_ASSIGN(ContextGLES);
 };
 
diff --git a/impeller/renderer/backend/gles/proc_table_gles.h b/impeller/renderer/backend/gles/proc_table_gles.h
index 6fb00e83c4a5a..32b36b69f9a46 100644
--- a/impeller/renderer/backend/gles/proc_table_gles.h
+++ b/impeller/renderer/backend/gles/proc_table_gles.h
@@ -163,7 +163,8 @@ struct GLProc {
   PROC(UseProgram);                          \
   PROC(VertexAttribPointer);                 \
   PROC(Viewport);                            \
-  PROC(ReadPixels);
+  PROC(ReadPixels);                          \
+  PROC(Finish);
 
 #define FOR_EACH_IMPELLER_GLES3_PROC(PROC) PROC(BlitFramebuffer);
 
diff --git a/impeller/renderer/backend/metal/command_buffer_mtl.h b/impeller/renderer/backend/metal/command_buffer_mtl.h
index 30dd3f6f5d6a4..b7ad3101305b5 100644
--- a/impeller/renderer/backend/metal/command_buffer_mtl.h
+++ b/impeller/renderer/backend/metal/command_buffer_mtl.h
@@ -13,6 +13,8 @@ namespace impeller {
 
 class CommandBufferMTL final : public CommandBuffer {
  public:
+  using SubmitCallback = std::function<void(id<MTLCommandBuffer>)>;
+
   // |CommandBuffer|
   ~CommandBufferMTL() override;
 
@@ -20,9 +22,11 @@ class CommandBufferMTL final : public CommandBuffer {
   friend class ContextMTL;
 
   id<MTLCommandBuffer> buffer_ = nullptr;
+  SubmitCallback submit_callback_ = nullptr;
 
   CommandBufferMTL(const std::weak_ptr<const Context>& context,
-                   id<MTLCommandQueue> queue);
+                   id<MTLCommandQueue> queue,
+                   SubmitCallback submit_callback);
 
   // |CommandBuffer|
   void SetLabel(const std::string& label) const override;
diff --git a/impeller/renderer/backend/metal/command_buffer_mtl.mm b/impeller/renderer/backend/metal/command_buffer_mtl.mm
index 2e8a5f7d8a5af..4702bced5ddbf 100644
--- a/impeller/renderer/backend/metal/command_buffer_mtl.mm
+++ b/impeller/renderer/backend/metal/command_buffer_mtl.mm
@@ -122,8 +122,11 @@ static bool LogMTLCommandBufferErrorIfPresent(id<MTLCommandBuffer> buffer) {
 }
 
 CommandBufferMTL::CommandBufferMTL(const std::weak_ptr<const Context>& context,
-                                   id<MTLCommandQueue> queue)
-    : CommandBuffer(context), buffer_(CreateCommandBuffer(queue)) {}
+                                   id<MTLCommandQueue> queue,
+                                   SubmitCallback submit_callback)
+    : CommandBuffer(context),
+      buffer_(CreateCommandBuffer(queue)),
+      submit_callback_(std::move(submit_callback)) {}
 
 CommandBufferMTL::~CommandBufferMTL() = default;
 
@@ -164,6 +167,10 @@ static bool LogMTLCommandBufferErrorIfPresent(id<MTLCommandBuffer> buffer) {
   }
 
   [buffer_ commit];
+  if (submit_callback_) {
+    submit_callback_(buffer_);
+  }
+
   [buffer_ waitUntilScheduled];
   buffer_ = nil;
   return true;
diff --git a/impeller/renderer/backend/metal/context_mtl.h b/impeller/renderer/backend/metal/context_mtl.h
index 1ba4740d09525..e5430319fd68f 100644
--- a/impeller/renderer/backend/metal/context_mtl.h
+++ b/impeller/renderer/backend/metal/context_mtl.h
@@ -39,6 +39,7 @@ class ContextMTL final : public Context,
  private:
   id<MTLDevice> device_ = nullptr;
   id<MTLCommandQueue> command_queue_ = nullptr;
+  id<MTLCommandBuffer> last_submitted_buffer_ = nullptr;
   std::shared_ptr<ShaderLibraryMTL> shader_library_;
   std::shared_ptr<PipelineLibraryMTL> pipeline_library_;
   std::shared_ptr<SamplerLibrary> sampler_library_;
@@ -67,6 +68,9 @@ class ContextMTL final : public Context,
   // |Context|
   std::shared_ptr<CommandBuffer> CreateCommandBuffer() const override;
 
+  // |Context|
+  bool WaitUntilCommandsCompleted() override;
+
   // |Context|
   std::shared_ptr<WorkQueue> GetWorkQueue() const override;
 
diff --git a/impeller/renderer/backend/metal/context_mtl.mm b/impeller/renderer/backend/metal/context_mtl.mm
index 379b7cf52fb5f..4e15b4273510b 100644
--- a/impeller/renderer/backend/metal/context_mtl.mm
+++ b/impeller/renderer/backend/metal/context_mtl.mm
@@ -226,14 +226,37 @@
     return nullptr;
   }
 
-  auto buffer = std::shared_ptr<CommandBufferMTL>(
-      new CommandBufferMTL(weak_from_this(), queue));
+  auto weak_this = weak_from_this();
+  auto buffer = std::shared_ptr<CommandBufferMTL>(new CommandBufferMTL(
+      weak_this, queue, [weak_this](id<MTLCommandBuffer> buffer) {
+        auto strong_this = weak_this.lock();
+        if (strong_this) {
+          auto& context_mtl =
+              ContextMTL::Cast(const_cast<Context&>(*strong_this));
+          context_mtl.last_submitted_buffer_ = buffer;
+        }
+      }));
   if (!buffer->IsValid()) {
     return nullptr;
   }
   return buffer;
 }
 
+// |Context|
+bool ContextMTL::WaitUntilCommandsCompleted() {
+  if (!last_submitted_buffer_) {
+    return true;
+  }
+
+  if (last_submitted_buffer_.status == MTLCommandBufferStatusCompleted) {
+    return true;
+  }
+
+  [last_submitted_buffer_ waitUntilCompleted];
+  last_submitted_buffer_ = nullptr;
+  return true;
+}
+
 std::shared_ptr<Allocator> ContextMTL::GetResourceAllocator() const {
   return resource_allocator_;
 }
diff --git a/impeller/renderer/backend/vulkan/context_vk.cc b/impeller/renderer/backend/vulkan/context_vk.cc
index e2002204cd13c..73b8b6679b1f6 100644
--- a/impeller/renderer/backend/vulkan/context_vk.cc
+++ b/impeller/renderer/backend/vulkan/context_vk.cc
@@ -528,6 +528,15 @@ std::shared_ptr<CommandBuffer> ContextVK::CreateCommandBuffer() const {
                                  surface_producer_.get());
 }
 
+bool ContextVK::WaitUntilCommandsCompleted() {
+  auto result = device_->waitIdle();
+  if (result != vk::Result::eSuccess) {
+    VALIDATION_LOG << "Failed to wait device idle: " << vk::to_string(result);
+    return false;
+  }
+  return true;
+}
+
 vk::Instance ContextVK::GetInstance() const {
   return *instance_;
 }
diff --git a/impeller/renderer/backend/vulkan/context_vk.h b/impeller/renderer/backend/vulkan/context_vk.h
index 44806548cd5af..ce5a572deda4e 100644
--- a/impeller/renderer/backend/vulkan/context_vk.h
+++ b/impeller/renderer/backend/vulkan/context_vk.h
@@ -136,6 +136,9 @@ class ContextVK final : public Context, public BackendCast<ContextVK, Context> {
   // |Context|
   std::shared_ptr<CommandBuffer> CreateCommandBuffer() const override;
 
+  // |Context|
+  bool WaitUntilCommandsCompleted() override;
+
   // |Context|
   PixelFormat GetColorAttachmentPixelFormat() const override;
 
diff --git a/impeller/renderer/context.h b/impeller/renderer/context.h
index 8ba839b8612c0..8a53620f92ff4 100644
--- a/impeller/renderer/context.h
+++ b/impeller/renderer/context.h
@@ -39,6 +39,8 @@ class Context : public std::enable_shared_from_this<Context> {
 
   virtual std::shared_ptr<CommandBuffer> CreateCommandBuffer() const = 0;
 
+  virtual bool WaitUntilCommandsCompleted() = 0;
+
   virtual std::shared_ptr<WorkQueue> GetWorkQueue() const = 0;
 
   //----------------------------------------------------------------------------
diff --git a/impeller/renderer/renderer_unittests.cc b/impeller/renderer/renderer_unittests.cc
index cfd3637f9a8c2..179b0f9c5ccb3 100644
--- a/impeller/renderer/renderer_unittests.cc
+++ b/impeller/renderer/renderer_unittests.cc
@@ -625,6 +625,8 @@ TEST_P(RendererTest, CanBlitTextureToBuffer) {
       if (!buffer->SubmitCommands()) {
         return false;
       }
+
+      context->WaitUntilCommandsCompleted();
     }
 
     {
diff --git a/shell/common/snapshot_controller_impeller.cc b/shell/common/snapshot_controller_impeller.cc
index 6e5d65b74769c..1b717ccbffe8b 100644
--- a/shell/common/snapshot_controller_impeller.cc
+++ b/shell/common/snapshot_controller_impeller.cc
@@ -63,6 +63,7 @@ sk_sp<DlImage> SnapshotControllerImpeller::DoMakeRasterSnapshot(
 
     std::shared_ptr<impeller::Image> image =
         picture.ToImage(*context, render_target_size);
+    context->GetContext()->WaitUntilCommandsCompleted();
     if (image) {
       return impeller::DlImageImpeller::Make(image->GetTexture());
     }