diff --git a/.github/workflows/dependabot-auto-merge.yml b/.github/workflows/dependabot-auto-merge.yml
index 946ee9f..7196b4a 100644
--- a/.github/workflows/dependabot-auto-merge.yml
+++ b/.github/workflows/dependabot-auto-merge.yml
@@ -16,7 +16,7 @@ jobs:
         id: metadata
         uses: dependabot/fetch-metadata@v1.1.1
         with:
-          github-token: '${{ secrets.GITHUB_TOKEN }}'
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
       - name: Enable auto-merge for Dependabot PRs
         if: ${{ steps.metadata.outputs.update-type == 'version-update:semver-patch' }}
         run: gh pr merge --auto --merge "$PR_URL"
diff --git a/pyproject.toml b/pyproject.toml
index c85bc93..f10bdf1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "m2stitch"
-version = "0.2.1"
+version = "0.2.2"
 description = "M2Stitch"
 authors = ["Yohsuke Fukai <ysk@yfukai.net>"]
 license = "MIT"
diff --git a/src/m2stitch/_constrained_refinement.py b/src/m2stitch/_constrained_refinement.py
index de2dacc..1f6e72c 100644
--- a/src/m2stitch/_constrained_refinement.py
+++ b/src/m2stitch/_constrained_refinement.py
@@ -90,6 +90,7 @@ def refine_translations(images: NumArray, grid: pd.DataFrame, r: Float) -> pd.Da
                 continue
             image1 = images[i1]
             image2 = images[i2]
+            W, H = image1.shape
 
             def overlap_ncc(params):
                 x, y = params
@@ -102,8 +103,8 @@ def overlap_ncc(params):
                 int(g[f"{direction}_y_second"]),
             ]
             limits = [
-                [init_values[0] - r, init_values[0] + r],
-                [init_values[1] - r, init_values[1] + r],
+                [max(-W + 1, init_values[0] - r), min(W - 1, init_values[0] + r)],
+                [max(-H + 1, init_values[1] - r), min(H - 1, init_values[1] + r)],
             ]
             values, ncc_value = find_local_max_integer_constrained(
                 overlap_ncc, np.array(init_values), np.array(limits)