diff --git a/python/core/auto_generated/qgsrelation.sip.in b/python/core/auto_generated/qgsrelation.sip.in
index 056f81fce45..a9e0fbf2189 100644
--- a/python/core/auto_generated/qgsrelation.sip.in
+++ b/python/core/auto_generated/qgsrelation.sip.in
@@ -36,7 +36,14 @@ class QgsRelation
 Default constructor. Creates an invalid relation.
 %End
     ~QgsRelation();
+
     QgsRelation( const QgsRelation &other );
+%Docstring
+Copies a relation.
+This makes a shallow copy, relations are implicitly shared and only duplicated when the copy is
+changed.
+%End
+
 
     static QgsRelation createFromXml( const QDomNode &node, QgsReadWriteContext &context );
 %Docstring
diff --git a/src/core/qgsrelation.h b/src/core/qgsrelation.h
index 127a4b7645b..3df389b5c1d 100644
--- a/src/core/qgsrelation.h
+++ b/src/core/qgsrelation.h
@@ -95,7 +95,19 @@ class CORE_EXPORT QgsRelation
      */
     QgsRelation();
     ~QgsRelation();
+
+    /**
+     * Copies a relation.
+     * This makes a shallow copy, relations are implicitly shared and only duplicated when the copy is
+     * changed.
+     */
     QgsRelation( const QgsRelation &other );
+
+    /**
+     * Copies a relation.
+     * This makes a shallow copy, relations are implicitly shared and only duplicated when the copy is
+     * changed.
+     */
     QgsRelation &operator=( const QgsRelation &other );
 
     /**