diff --git a/.github/workflows/integration-test.yml b/.github/workflows/integration-test.yml
index 2540c53..4650353 100644
--- a/.github/workflows/integration-test.yml
+++ b/.github/workflows/integration-test.yml
@@ -61,8 +61,10 @@ jobs:
         with:
           python-version: '3.10'
       - name: Install dependencies
+        # Pin virtualenv until hatch is fixed.
+        # See https://github.com/pypa/hatch/issues/2193
         run: |
-          pip install --no-cache-dir hatch
+          pip install --no-cache-dir hatch 'virtualenv<21'
       - name: Run integration tests
         env:
           AWS_REGION: us-east-1
diff --git a/.github/workflows/pypi-publish-on-release.yml b/.github/workflows/pypi-publish-on-release.yml
index ec2a940..d7fbd94 100644
--- a/.github/workflows/pypi-publish-on-release.yml
+++ b/.github/workflows/pypi-publish-on-release.yml
@@ -32,9 +32,11 @@ jobs:
         python-version: '3.10'
 
     - name: Install dependencies
+      # Pin virtualenv until hatch is fixed.
+      # See https://github.com/pypa/hatch/issues/2193
       run: |
         python -m pip install --upgrade pip
-        pip install hatch twine
+        pip install hatch twine 'virtualenv<21'
 
     - name: Validate version
       run: |
diff --git a/.github/workflows/test-lint.yml b/.github/workflows/test-lint.yml
index 52a32f1..5abdc13 100644
--- a/.github/workflows/test-lint.yml
+++ b/.github/workflows/test-lint.yml
@@ -85,8 +85,10 @@ jobs:
           cache: 'pip'
 
       - name: Install dependencies
+        # Pin virtualenv until hatch is fixed.
+        # See https://github.com/pypa/hatch/issues/2193
         run: |
-          pip install --no-cache-dir hatch
+          pip install --no-cache-dir hatch 'virtualenv<21'
 
       - name: Run lint
         id: lint
diff --git a/pyproject.toml b/pyproject.toml
index 511b56e..e9d00a0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,6 +26,11 @@ dependencies = [
     "tenacity>=8.0.0,<10.0.0",
 ]
 
+[tool.hatch.env]
+requires = [
+    "virtualenv==20.26.6",
+]
+
 [tool.hatch.build.targets.wheel]
 packages = ["src/strands_evals"]