diff --git a/src/app/qgsmaptoolpinlabels.h b/src/app/qgsmaptoolpinlabels.h
index 9c3540ea127f..b019dda455c2 100644
--- a/src/app/qgsmaptoolpinlabels.h
+++ b/src/app/qgsmaptoolpinlabels.h
@@ -24,7 +24,7 @@
 #include "qgscoordinatetransform.h"
 
 class QgsHighlight;
-struct QgsLabelPosition;
+class QgsLabelPosition;
 
 /**A map tool for pinning (writing to attribute table) and unpinning labelpositions and rotation*/
 class QgsMapToolPinLabels: public QgsMapToolLabel
diff --git a/src/app/qgsmaptoolshowhidelabels.h b/src/app/qgsmaptoolshowhidelabels.h
index 85f32ef74ae1..ae83e9379e0d 100644
--- a/src/app/qgsmaptoolshowhidelabels.h
+++ b/src/app/qgsmaptoolshowhidelabels.h
@@ -23,7 +23,7 @@
 
 
 /**A map tool for showing or hidding a feature's label*/
-class QgsMapToolShowHideLabels: public QgsMapToolLabel
+class QgsMapToolShowHideLabels : public QgsMapToolLabel
 {
     Q_OBJECT
 
diff --git a/src/core/diagram/qgsdiagram.h b/src/core/diagram/qgsdiagram.h
index 91cece7e5e96..1f96ff064fec 100644
--- a/src/core/diagram/qgsdiagram.h
+++ b/src/core/diagram/qgsdiagram.h
@@ -21,8 +21,8 @@
 
 class QPainter;
 class QPointF;
-struct QgsDiagramSettings;
-struct QgsDiagramInterpolationSettings;
+class QgsDiagramSettings;
+class QgsDiagramInterpolationSettings;
 
 class QgsRenderContext;
 
diff --git a/src/core/diagram/qgshistogramdiagram.h b/src/core/diagram/qgshistogramdiagram.h
index e27111c2471d..25d186254007 100644
--- a/src/core/diagram/qgshistogramdiagram.h
+++ b/src/core/diagram/qgshistogramdiagram.h
@@ -25,8 +25,8 @@
 
 class QPainter;
 class QPointF;
-struct QgsDiagramSettings;
-struct QgsDiagramInterpolationSettings;
+class QgsDiagramSettings;
+class QgsDiagramInterpolationSettings;
 
 class QgsRenderContext;
 
diff --git a/src/core/diagram/qgspiediagram.h b/src/core/diagram/qgspiediagram.h
index 9390e21fa409..1ccc51c58247 100644
--- a/src/core/diagram/qgspiediagram.h
+++ b/src/core/diagram/qgspiediagram.h
@@ -24,8 +24,8 @@
 
 class QPainter;
 class QPointF;
-struct QgsDiagramSettings;
-struct QgsDiagramInterpolationSettings;
+class QgsDiagramSettings;
+class QgsDiagramInterpolationSettings;
 
 class QgsRenderContext;
 
diff --git a/src/core/diagram/qgstextdiagram.h b/src/core/diagram/qgstextdiagram.h
index 8d6e59133ae7..83fba3c165ec 100644
--- a/src/core/diagram/qgstextdiagram.h
+++ b/src/core/diagram/qgstextdiagram.h
@@ -24,8 +24,8 @@
 
 class QPainter;
 class QPointF;
-struct QgsDiagramSettings;
-struct QgsDiagramInterpolationSettings;
+class QgsDiagramSettings;
+class QgsDiagramInterpolationSettings;
 
 class QgsRenderContext;