diff --git a/src/scope/core/pipelines/reward_forcing/pipeline.py b/src/scope/core/pipelines/reward_forcing/pipeline.py
index 089ce5b6..f24300ce 100644
--- a/src/scope/core/pipelines/reward_forcing/pipeline.py
+++ b/src/scope/core/pipelines/reward_forcing/pipeline.py
@@ -195,6 +195,14 @@ def _generate(self, **kwargs) -> torch.Tensor:
         if "vace_ref_images" not in kwargs:
             self.state.set("vace_ref_images", None)
 
+        # Clear extension mode parameters from state if not provided to prevent reuse on non-extension chunks
+        if "extension_mode" not in kwargs:
+            self.state.set("extension_mode", None)
+        if "first_frame_image" not in kwargs:
+            self.state.set("first_frame_image", None)
+        if "last_frame_image" not in kwargs:
+            self.state.set("last_frame_image", None)
+
         if self.state.get("denoising_step_list") is None:
             self.state.set("denoising_step_list", DEFAULT_DENOISING_STEP_LIST)
 
diff --git a/src/scope/core/pipelines/streamdiffusionv2/pipeline.py b/src/scope/core/pipelines/streamdiffusionv2/pipeline.py
index ef8f63fc..82b54cb2 100644
--- a/src/scope/core/pipelines/streamdiffusionv2/pipeline.py
+++ b/src/scope/core/pipelines/streamdiffusionv2/pipeline.py
@@ -202,6 +202,14 @@ def _generate(self, **kwargs) -> torch.Tensor:
         if "vace_ref_images" not in kwargs:
             self.state.set("vace_ref_images", None)
 
+        # Clear extension mode parameters from state if not provided to prevent reuse on non-extension chunks
+        if "extension_mode" not in kwargs:
+            self.state.set("extension_mode", None)
+        if "first_frame_image" not in kwargs:
+            self.state.set("first_frame_image", None)
+        if "last_frame_image" not in kwargs:
+            self.state.set("last_frame_image", None)
+
         if self.state.get("denoising_step_list") is None:
             self.state.set("denoising_step_list", DEFAULT_DENOISING_STEP_LIST)