diff --git a/src/3d/symbols/qgsline3dsymbol_p.cpp b/src/3d/symbols/qgsline3dsymbol_p.cpp
index 14c81b4f27a0..0088aeba2fdb 100644
--- a/src/3d/symbols/qgsline3dsymbol_p.cpp
+++ b/src/3d/symbols/qgsline3dsymbol_p.cpp
@@ -375,7 +375,12 @@ void QgsThickLine3DSymbolHandler::processFeature( const QgsFeature &f, const Qgs
   QgsLineVertexData &out = mSelectedIds.contains( f.id() ) ? outSelected : outNormal;
 
   QgsGeometry geom = f.geometry();
+  // segmentize curved geometries if necessary
+  if ( QgsWkbTypes::isCurvedType( geom.constGet()->wkbType() ) )
+    geom = QgsGeometry( geom.constGet()->segmentize() );
+
   const QgsAbstractGeometry *g = geom.constGet();
+
   if ( const QgsLineString *ls = qgsgeometry_cast<const QgsLineString *>( g ) )
   {
     out.addLineString( *ls );
diff --git a/src/3d/symbols/qgslinevertexdata_p.cpp b/src/3d/symbols/qgslinevertexdata_p.cpp
index c438caad2aa4..a9d1987a2325 100644
--- a/src/3d/symbols/qgslinevertexdata_p.cpp
+++ b/src/3d/symbols/qgslinevertexdata_p.cpp
@@ -125,7 +125,6 @@ void QgsLineVertexData::addLineString( const QgsLineString &lineString, float ex
   indexes << 0;  // add primitive restart
 }
 
-
 void QgsLineVertexData::addVerticalLines( const QgsLineString &lineString, float verticalLength, float extraHeightOffset )
 {
   QgsPoint centroid;
diff --git a/tests/src/3d/testqgs3drendering.cpp b/tests/src/3d/testqgs3drendering.cpp
index bf33996f212e..2ceb2597900f 100644
--- a/tests/src/3d/testqgs3drendering.cpp
+++ b/tests/src/3d/testqgs3drendering.cpp
@@ -74,6 +74,7 @@ class TestQgs3DRendering : public QObject
     void testExtrudedPolygonsDataDefined();
     void testPolygonsEdges();
     void testLineRendering();
+    void testLineRenderingCurved();
     void testBufferedLineRendering();
     void testBufferedLineRenderingWidth();
     void testMapTheme();
@@ -564,6 +565,63 @@ void TestQgs3DRendering::testLineRendering()
   delete layerLines;
 }
 
+void TestQgs3DRendering::testLineRenderingCurved()
+{
+  // test rendering of compound curve lines works
+  QgsRectangle fullExtent( 0, 0, 1000, 1000 );
+
+  QgsVectorLayer *layerLines = new QgsVectorLayer( "CompoundCurve?crs=EPSG:27700", "lines", "memory" );
+
+  QgsLine3DSymbol *lineSymbol = new QgsLine3DSymbol;
+  lineSymbol->setRenderAsSimpleLines( true );
+  lineSymbol->setWidth( 10 );
+  QgsSimpleLineMaterialSettings mat;
+  mat.setAmbient( Qt::red );
+  lineSymbol->setMaterial( mat.clone() );
+  layerLines->setRenderer3D( new QgsVectorLayer3DRenderer( lineSymbol ) );
+
+  QVector<QgsPoint> pts;
+  pts << QgsPoint( 0, 0, 10 ) << QgsPoint( 0, 1000, 10 ) << QgsPoint( 1000, 1000, 10 ) << QgsPoint( 1000, 0, 10 );
+  std::unique_ptr< QgsCompoundCurve > curve = std::make_unique< QgsCompoundCurve >();
+  curve->addCurve( new QgsLineString( pts ) );
+  pts.clear();
+  pts << QgsPoint( 1000, 0, 10 ) << QgsPoint( 1000, 0, 500 ) << QgsPoint( 1000, 1000, 500 ) << QgsPoint( 0, 1000, 500 ) << QgsPoint( 0, 0, 500 );
+  curve->addCurve( new QgsLineString( pts ) );
+
+  QgsFeature f1( layerLines->fields() );
+  f1.setGeometry( QgsGeometry( std::move( curve ) ) );
+  QgsFeatureList flist;
+  flist << f1;
+  layerLines->dataProvider()->addFeatures( flist );
+
+  Qgs3DMapSettings *map = new Qgs3DMapSettings;
+  map->setCrs( mProject->crs() );
+  map->setOrigin( QgsVector3D( fullExtent.center().x(), fullExtent.center().y(), 0 ) );
+  map->setLayers( QList<QgsMapLayer *>() << layerLines );
+
+  QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
+  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setExtent( fullExtent );
+  map->setTerrainGenerator( flatTerrain );
+
+  QgsOffscreen3DEngine engine;
+  Qgs3DMapScene *scene = new Qgs3DMapScene( *map, &engine );
+  engine.setRootEntity( scene );
+
+  // look from the top
+  scene->cameraController()->setLookingAtPoint( QgsVector3D( 0, 0, 0 ), 2500, 0, 0 );
+
+  // When running the test on Travis, it would initially return empty rendered image.
+  // Capturing the initial image and throwing it away fixes that. Hopefully we will
+  // find a better fix in the future.
+  Qgs3DUtils::captureSceneImage( engine, scene );
+
+  QImage img = Qgs3DUtils::captureSceneImage( engine, scene );
+  QVERIFY( renderCheck( "line_rendering_1", img, 40 ) );
+
+  delete layerLines;
+}
+
 void TestQgs3DRendering::testBufferedLineRendering()
 {
   QgsRectangle fullExtent = mLayerDtm->extent();