diff --git a/python/PyQt6/core/auto_generated/qgsvector3d.sip.in b/python/PyQt6/core/auto_generated/qgsvector3d.sip.in
index 9fe5178311be..424235ebde78 100644
--- a/python/PyQt6/core/auto_generated/qgsvector3d.sip.in
+++ b/python/PyQt6/core/auto_generated/qgsvector3d.sip.in
@@ -84,6 +84,8 @@ Sets vector coordinates
 
     QgsVector3D operator-( const QgsVector3D &other ) const /HoldGIL/;
 
+    const QgsVector3D operator-() const /HoldGIL/;
+
     QgsVector3D operator *( const double factor ) const /HoldGIL/;
 
     QgsVector3D operator /( const double factor ) const /HoldGIL/;
diff --git a/python/core/auto_generated/qgsvector3d.sip.in b/python/core/auto_generated/qgsvector3d.sip.in
index 9fe5178311be..424235ebde78 100644
--- a/python/core/auto_generated/qgsvector3d.sip.in
+++ b/python/core/auto_generated/qgsvector3d.sip.in
@@ -84,6 +84,8 @@ Sets vector coordinates
 
     QgsVector3D operator-( const QgsVector3D &other ) const /HoldGIL/;
 
+    const QgsVector3D operator-() const /HoldGIL/;
+
     QgsVector3D operator *( const double factor ) const /HoldGIL/;
 
     QgsVector3D operator /( const double factor ) const /HoldGIL/;
diff --git a/src/core/qgsvector3d.h b/src/core/qgsvector3d.h
index 621bf1b81b42..a7ee846502c0 100644
--- a/src/core/qgsvector3d.h
+++ b/src/core/qgsvector3d.h
@@ -99,6 +99,16 @@ class CORE_EXPORT QgsVector3D
       return QgsVector3D( mX - other.mX, mY - other.mY, mZ - other.mZ );
     }
 
+    /**
+     * Swaps the sign of the components of the vector.
+     *
+     * \since QGIS 3.40
+     */
+    const QgsVector3D operator-() const SIP_HOLDGIL
+    {
+      return QgsVector3D( -mX, -mY, -mZ );
+    }
+
     //! Returns a new vector multiplied by scalar
     QgsVector3D operator *( const double factor ) const SIP_HOLDGIL
     {
diff --git a/tests/src/core/testqgsvector.cpp b/tests/src/core/testqgsvector.cpp
index 6cbc22773243..2a41ab6369d5 100644
--- a/tests/src/core/testqgsvector.cpp
+++ b/tests/src/core/testqgsvector.cpp
@@ -84,6 +84,12 @@ void TestQgsVector::vector3d()
   QCOMPARE( QgsVector3D::perpendicularPoint( QgsVector3D( 0.0, 0.0, 0.0 ), QgsVector3D( 0.0, 5.0, 0.0 ), QgsVector3D( 1.0, 4.0, 0.0 ) ), QgsVector3D( 0.0, 4.0, 0.0 ) );
   QCOMPARE( QgsVector3D::perpendicularPoint( QgsVector3D( 0.0, 0.0, 5.0 ), QgsVector3D( 0.0, 0.0, 10.0 ), QgsVector3D( 2.0, 4.0, 7 ) ), QgsVector3D( 0.0, 0.0, 7.0 ) );
   QCOMPARE( QgsVector3D::perpendicularPoint( QgsVector3D( 0.0, 0.0, 5.0 ), QgsVector3D( 0.0, 5.0, 10.0 ), QgsVector3D( 1.0, 4.0, 5.0 ) ).toString( 2 ), QgsVector3D( 0.0, 2.0, 7.0 ).toString( 2 ) );
+
+  // operator -
+  QgsVector3D v1( 1.0, -2.0, 5.0 );
+  QgsVector3D v2( -3.0, 12.0, 1.0 );
+  QCOMPARE( v1 - v2, QgsVector3D( 4.0, -14.0, 4.0 ) );
+  QCOMPARE( -v2, QgsVector3D( 3.0, -12.0, -1.0 ) );
 }
 
 void TestQgsVector::setters()