diff --git a/.github/workflows/autofix-pre-commit.yaml b/.github/workflows/autofix-pre-commit.yaml
index e5da9c8a..4cd60b57 100644
--- a/.github/workflows/autofix-pre-commit.yaml
+++ b/.github/workflows/autofix-pre-commit.yaml
@@ -20,8 +20,8 @@ permissions:
 jobs:
     autofix-pre-commit:
         env:
-            UV_FROZEN: true
-            UV_NO_SYNC: true
+            UV_FROZEN: "true"
+            UV_NO_SYNC: "true"
             UV_PYTHON_DOWNLOADS: never
         name: Run pre-commit hooks and commit any auto-fixes
         runs-on: ubuntu-latest
diff --git a/.github/workflows/check-build-deploy.yaml b/.github/workflows/check-build-deploy.yaml
index 3e79c6e7..41588aa0 100644
--- a/.github/workflows/check-build-deploy.yaml
+++ b/.github/workflows/check-build-deploy.yaml
@@ -35,8 +35,8 @@ jobs:
 
     flake8:  # yamllint disable-line rule:key-ordering
         env:
-            UV_FROZEN: true
-            UV_NO_SYNC: true
+            UV_FROZEN: "true"
+            UV_NO_SYNC: "true"
             UV_PYTHON_DOWNLOADS: never
         name: Lint code with Flake8
         runs-on: ubuntu-latest
@@ -64,8 +64,8 @@ jobs:
 
     mypy:  # yamllint disable-line rule:key-ordering
         env:
-            UV_FROZEN: true
-            UV_NO_SYNC: true
+            UV_FROZEN: "true"
+            UV_NO_SYNC: "true"
             UV_PYTHON_DOWNLOADS: never
         name: Type-check code with mypy
         needs: [uv-check]
@@ -155,8 +155,8 @@ jobs:
 
     pymarkdown:  # yamllint disable-line rule:key-ordering
         env:
-            UV_FROZEN: true
-            UV_NO_SYNC: true
+            UV_FROZEN: "true"
+            UV_NO_SYNC: "true"
             UV_PYTHON_DOWNLOADS: never
         name: Lint Markdown files using PyMarkdown
         runs-on: ubuntu-latest
@@ -184,8 +184,8 @@ jobs:
 
     pytest:  # yamllint disable-line rule:key-ordering
         env:
-            UV_FROZEN: true
-            UV_NO_SYNC: true
+            UV_FROZEN: "true"
+            UV_NO_SYNC: "true"
             UV_PYTHON_DOWNLOADS: never
         name: Run test suite with pytest
         needs: [uv-check]
@@ -239,8 +239,8 @@ jobs:
 
     ruff-lint:  # yamllint disable-line rule:key-ordering
         env:
-            UV_FROZEN: true
-            UV_NO_SYNC: true
+            UV_FROZEN: "true"
+            UV_NO_SYNC: "true"
             UV_PYTHON_DOWNLOADS: never
         name: Lint code with ruff
         runs-on: ubuntu-latest