diff --git a/.github/workflows/build-goopylib.yml b/.github/workflows/build-goopylib.yml
index e7ca06c7..104d3eef 100644
--- a/.github/workflows/build-goopylib.yml
+++ b/.github/workflows/build-goopylib.yml
@@ -36,7 +36,8 @@ jobs:
         with:
           submodules: 'recursive'
 
-      - uses: actions/setup-node@v4
+      - uses: openrndr/setup-opengl@v1.1
+      - run: xvfb-run glxinfo
 
       - name: Configure CMake
         run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
diff --git a/src/objects/Line.cpp b/src/objects/Line.cpp
index 7abf8724..71daafe5 100644
--- a/src/objects/Line.cpp
+++ b/src/objects/Line.cpp
@@ -8,7 +8,7 @@ namespace {
         thickness /= 2;
         float theta = atan((p2.y - p1.y) / (p2.x - p1.x));
 
-        if (isnan(theta)) {
+        if (std::isnan(theta)) {
             return {thickness, thickness};
         }