diff --git a/src/core/qgsogcutils.cpp b/src/core/qgsogcutils.cpp
index 75835c9fffb2..a68a730f9ba2 100644
--- a/src/core/qgsogcutils.cpp
+++ b/src/core/qgsogcutils.cpp
@@ -1955,6 +1955,7 @@ QDomElement QgsOgcUtils::expressionToOgcExpression( const QgsExpression &express
     case QgsExpressionNode::ntFunction:
     case QgsExpressionNode::ntLiteral:
     case QgsExpressionNode::ntColumnRef:
+    case QgsExpressionNode::ntUnaryOperator:
     {
       QgsOgcUtilsExprToFilter utils( doc, gmlVersion, filterVersion, QString(), QString(), geometryName, srsName, honourAxisOrientation, invertAxisOrientation, fieldNameToXPathMap, namespacePrefixToUriMap );
       const QDomElement exprRootElem = utils.expressionNodeToOgcFilter( node, &exp, &context );
diff --git a/tests/src/python/test_qgssymbollayer_createsld.py b/tests/src/python/test_qgssymbollayer_createsld.py
index 9de983114773..d31f6d1ce153 100644
--- a/tests/src/python/test_qgssymbollayer_createsld.py
+++ b/tests/src/python/test_qgssymbollayer_createsld.py
@@ -83,6 +83,12 @@ def testSimpleMarkerRotation(self):
 
         self.assertStaticRotation(root, '50')
 
+        symbol.setAngle(-50)
+        dom, root = self.symbolToSld(symbol)
+        # print( "Simple marker rotation: " + root.ownerDocument().toString())
+
+        self.assertStaticRotation(root, '-50')
+
     def testSimpleMarkerUnitDefault(self):
         symbol = QgsSimpleMarkerSymbolLayer(
             QgsSimpleMarkerSymbolLayerBase.Shape.Star, color=QColor(255, 0, 0), strokeColor=QColor(0, 255, 0), size=10)
@@ -145,6 +151,10 @@ def testSvgMarkerUnitDefault(self):
         self.assertStaticRotation(root, '90')
         self.assertStaticDisplacement(root, 18, 36)
 
+        symbol.setAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def testSvgMarkerUnitPixels(self):
         symbol = QgsSvgMarkerSymbolLayer('symbols/star.svg', 10, 0)
         symbol.setFillColor(QColor("blue"))
@@ -178,6 +188,10 @@ def testFontMarkerUnitDefault(self):
         self.assertStaticRotation(root, '45')
         self.assertStaticDisplacement(root, 18, 36)
 
+        symbol.setAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def testFontMarkerUnitPixel(self):
         symbol = QgsFontMarkerSymbolLayer('sans', ',', 10, QColor('black'), 45)
         symbol.setOffset(QPointF(5, 10))
@@ -190,6 +204,10 @@ def testFontMarkerUnitPixel(self):
         self.assertStaticRotation(root, '45')
         self.assertStaticDisplacement(root, 5, 10)
 
+        symbol.setAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def createEllipseSymbolLayer(self):
         # No way to build it programmatically...
         mTestName = 'QgsEllipseSymbolLayer'
@@ -348,6 +366,10 @@ def testSvgFillDefault(self):
         lineSymbolizer = root.elementsByTagName('se:LineSymbolizer').item(0).toElement()
         self.assertStrokeWidth(lineSymbolizer, 1, 36)
 
+        symbol.setAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def testSvgFillPixel(self):
         symbol = QgsSVGFillSymbolLayer('test/star.svg', 10, 45)
         symbol.setSubSymbol(QgsLineSymbol())
@@ -373,6 +395,10 @@ def testSvgFillPixel(self):
         lineSymbolizer = root.elementsByTagName('se:LineSymbolizer').item(0).toElement()
         self.assertStrokeWidth(lineSymbolizer, 1, 10)
 
+        symbol.setAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def testLineFillDefault(self):
         symbol = QgsLinePatternFillSymbolLayer()
         symbol.setLineAngle(45)
@@ -387,6 +413,10 @@ def testLineFillDefault(self):
         self.assertStaticSize(root, '18')
         self.assertStaticDisplacement(root, 15, 9)
 
+        symbol.setLineAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def testLineFillPixels(self):
         symbol = QgsLinePatternFillSymbolLayer()
         symbol.setLineAngle(45)
@@ -402,6 +432,10 @@ def testLineFillPixels(self):
         self.assertStaticSize(root, '5')
         self.assertStaticDisplacement(root, 4.25, 2.63)
 
+        symbol.setLineAngle(-45)
+        dom, root = self.symbolToSld(symbol)
+        self.assertStaticRotation(root, '-45')
+
     def testPointFillDefault(self):
         symbol = QgsPointPatternFillSymbolLayer()
         dom, root = self.symbolToSld(symbol)