diff --git a/.github/workflows/build-ultraplot.yml b/.github/workflows/build-ultraplot.yml
index 8746dda49..ec69464a6 100644
--- a/.github/workflows/build-ultraplot.yml
+++ b/.github/workflows/build-ultraplot.yml
@@ -5,13 +5,17 @@ on:
       python-version:
         required: true
         type: string
-      locale:
+      matplotlib-version:
         required: true
         type: string
 
+env:
+  LC_ALL: en_US.UTF-8
+  LANG: en_US.UTF-8
+
 jobs:
   build-ultraplot:
-    name: Test Python ${{ inputs.python-version }}
+    name: Test Python ${{ inputs.python-version }} with ${{ inputs.matplotlib-version }}
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
@@ -23,6 +27,7 @@ jobs:
           create-args: >-
             --verbose
             python=${{ inputs.python-version }}
+            matplotlib=${{ inputs.matplotlib-version }}
           cache-environment: true
           cache-downloads: false
 
@@ -50,6 +55,7 @@ jobs:
           create-args: >-
             --verbose
             python=${{ inputs.python-version }}
+            matplotlib=${{ inputs.matplotlib-version }}
           cache-environment: true
           cache-downloads: false
 
@@ -79,5 +85,5 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v4
         with:
-          name: failed-comparisons-${{ inputs.python-version }}-${{ inputs.locale }}
+          name: failed-comparisons-${{ inputs.python-version }}-${{ inputs.matplotlib-version }}
           path: results/*
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 67ac6369c..76426b176 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -6,10 +6,11 @@ on:
     branches: [main, devel]
 
 jobs:
-  get-python-versions:
+  get-versions:
     runs-on: ubuntu-latest
     outputs:
       python-versions: ${{ steps.set-versions.outputs.python-versions }}
+      matplotlib-versions: ${{ steps.set-versions.outputs.matplotlib-versions }}
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -38,7 +39,7 @@ jobs:
           min_version = re.search(r">=(\d+\.\d+)", python_req)
           max_version = re.search(r"<(\d+\.\d+)", python_req)
 
-          versions = []
+          python_versions = []
           if min_version and max_version:
               # Convert version strings to tuples
               min_v = tuple(map(int, min_version.group(1).split(".")))
@@ -47,26 +48,70 @@ jobs:
               # Generate version list
               current = min_v
               while current < max_v:
-                  versions.append(".".join(map(str, current)))
+                  python_versions.append(".".join(map(str, current)))
                   current = (current[0], current[1] + 1)
 
-          # Print as JSON array
-          print(json.dumps(versions))
+
+          # parse MPL versions
+          mpl_req = None
+          for d in data["project"]["dependencies"]:
+            if d.startswith("matplotlib"):
+              mpl_req = d
+              break
+          assert mpl_req is not None, "matplotlib version not found in dependencies"
+          min_version = re.search(r">=(\d+\.\d+)", mpl_req)
+          max_version = re.search(r"<(\d+\.\d+)", mpl_req)
+
+          mpl_versions = []
+          if min_version and max_version:
+              # Convert version strings to tuples
+              min_v = tuple(map(int, min_version.group(1).split(".")))
+              max_v = tuple(map(int, max_version.group(1).split(".")))
+
+              # Generate version list
+              current = min_v
+              while current < max_v:
+                  mpl_versions.append(".".join(map(str, current)))
+                  current = (current[0], current[1] + 1)
+
+          # If no versions found, default to 3.9
+          if not mpl_versions:
+              mpl_versions = ["3.9"]
+
+          # Create output dictionary
+          output = {
+              "python_versions": python_versions,
+              "matplotlib_versions": mpl_versions
+          }
+
+          # Print as JSON
+          print(json.dumps(output))
           EOF
 
           # Run the script and capture output
-          VERSIONS=$(python3 get_versions.py)
-          echo "Detected versions: ${VERSIONS}"  # Debug output
-          echo "python-versions=${VERSIONS}" >> $GITHUB_OUTPUT
+          OUTPUT=$(python3 get_versions.py)
+          PYTHON_VERSIONS=$(echo $OUTPUT | jq -r '.python_versions')
+          MPL_VERSIONS=$(echo $OUTPUT | jq -r '.matplotlib_versions')
+
+          echo "Detected Python versions: ${PYTHON_VERSIONS}"
+          echo "Detected Matplotlib versions: ${MPL_VERSIONS}"
+          echo "python-versions=$(echo $PYTHON_VERSIONS | jq -c)" >> $GITHUB_OUTPUT
+          echo "matplotlib-versions=$(echo $MPL_VERSIONS | jq -c)" >> $GITHUB_OUTPUT
 
   build:
-    needs: get-python-versions
+    needs: get-versions
     strategy:
       matrix:
-        python-version: ${{ fromJson(needs.get-python-versions.outputs.python-versions) }}
-        locale: ["en_US.UTF-8", "C.UTF-8"]
+        python-version: ${{ fromJson(needs.get-versions.outputs.python-versions) }}
+        matplotlib-version: ${{ fromJson(needs.get-versions.outputs.matplotlib-versions) }}
       fail-fast: false
     uses: ./.github/workflows/build-ultraplot.yml
     with:
       python-version: ${{ matrix.python-version }}
-      locale: ${{ matrix.locale }}
+      matplotlib-version: ${{ matrix.matplotlib-version }}
+
+  build-success:
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "All tests passed successfully!"
diff --git a/pyproject.toml b/pyproject.toml
index 42be755e4..2cf743f81 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,10 +30,12 @@ classifiers = [
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Framework :: Matplotlib :: 3.9",
+    # "Framework :: Matplotlib :: 3.10" # add when basemap is updated
 ]
 dependencies= [
     "numpy>=1.26.0",
-    "matplotlib>=3.9"
+    "matplotlib>=3.9,<3.10"  # bump to 3.11 when basemap is updated
 ]
 dynamic = ["version"]