diff --git a/src/core/symbology/qgsrulebasedrenderer.cpp b/src/core/symbology/qgsrulebasedrenderer.cpp
index 590afe32b722..c228d5c45ba8 100644
--- a/src/core/symbology/qgsrulebasedrenderer.cpp
+++ b/src/core/symbology/qgsrulebasedrenderer.cpp
@@ -1221,8 +1221,9 @@ void QgsRuleBasedRenderer::refineRuleCategories( QgsRuleBasedRenderer::Rule *ini
       value = QString::number( cat.value().toDouble(), 'f', 4 );
     else
       value = QgsExpression::quotedString( cat.value().toString() );
-    QString filter = QStringLiteral( "%1 = %2" ).arg( attr, value );
-    QString label = filter;
+    const QString filter = QStringLiteral( "%1 = %2" ).arg( attr, value );
+    const QString label = !cat.label().isEmpty() ? cat.label() :
+                          cat.value().isValid() ? value : QString();
     initialRule->appendChild( new Rule( cat.symbol()->clone(), 0, 0, filter, label ) );
   }
 }
@@ -1254,7 +1255,7 @@ void QgsRuleBasedRenderer::refineRuleRanges( QgsRuleBasedRenderer::Rule *initial
                      QString::number( rng.lowerValue(), 'f', 4 ),
                      QString::number( rng.upperValue(), 'f', 4 ) );
     firstRange = false;
-    QString label =  rng.label().isEmpty() ? filter : rng.label();
+    QString label = rng.label().isEmpty() ? filter : rng.label();
     initialRule->appendChild( new Rule( rng.symbol()->clone(), 0, 0, filter, label ) );
   }
 }
diff --git a/tests/src/python/test_qgsrulebasedrenderer.py b/tests/src/python/test_qgsrulebasedrenderer.py
index 68f1f9ac25ee..16d801dd6509 100644
--- a/tests/src/python/test_qgsrulebasedrenderer.py
+++ b/tests/src/python/test_qgsrulebasedrenderer.py
@@ -201,12 +201,16 @@ def testRefineWithCategories(self):
         # First, try with a field based category (id)
         cats = []
         cats.append(QgsRendererCategory(1, QgsMarkerSymbol(), "id 1"))
-        cats.append(QgsRendererCategory(2, QgsMarkerSymbol(), "id 2"))
+        cats.append(QgsRendererCategory(2, QgsMarkerSymbol(), ''))
+        cats.append(QgsRendererCategory(None, QgsMarkerSymbol(), ''))
         c = QgsCategorizedSymbolRenderer("id", cats)
 
         QgsRuleBasedRenderer.refineRuleCategories(self.r2, c)
         self.assertEqual(self.r2.children()[0].filterExpression(), '"id" = 1')
         self.assertEqual(self.r2.children()[1].filterExpression(), '"id" = 2')
+        self.assertEqual(self.r2.children()[0].label(), 'id 1')
+        self.assertEqual(self.r2.children()[1].label(), '2')
+        self.assertEqual(self.r2.children()[2].label(), '')
 
         # Next try with an expression based category
         cats = []
@@ -217,6 +221,8 @@ def testRefineWithCategories(self):
         QgsRuleBasedRenderer.refineRuleCategories(self.r1, c)
         self.assertEqual(self.r1.children()[0].filterExpression(), 'id + 1 = 1')
         self.assertEqual(self.r1.children()[1].filterExpression(), 'id + 1 = 2')
+        self.assertEqual(self.r1.children()[0].label(), 'result 1')
+        self.assertEqual(self.r1.children()[1].label(), 'result 2')
 
         # Last try with an expression which is just a quoted field name
         cats = []
@@ -227,6 +233,8 @@ def testRefineWithCategories(self):
         QgsRuleBasedRenderer.refineRuleCategories(self.r3, c)
         self.assertEqual(self.r3.children()[0].filterExpression(), '"id" = 1')
         self.assertEqual(self.r3.children()[1].filterExpression(), '"id" = 2')
+        self.assertEqual(self.r3.children()[0].label(), 'result 1')
+        self.assertEqual(self.r3.children()[1].label(), 'result 2')
 
     def testRefineWithRanges(self):
         # Test refining rule with ranges (refs #10815)