diff --git a/src/gfx.cpp b/src/gfx.cpp
index 6039946fc6..a5e5772050 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -1416,16 +1416,6 @@ void DrawMouseCursor()
 	_cursor.dirty = false;
 }
 
-/**
- * Repaints a specific rectangle of the screen.
- *
- * @param left,top,right,bottom The area of the screen that needs repainting
- * @pre The rectangle should have been previously marked dirty with \c AddDirtyBlock.
- * @see AddDirtyBlock
- * @see DrawDirtyBlocks
- * @ingroup dirty
- *
- */
 void RedrawScreenRect(int left, int top, int right, int bottom)
 {
 	assert(right <= _screen.width && bottom <= _screen.height);
@@ -1448,9 +1438,7 @@ void RedrawScreenRect(int left, int top, int right, int bottom)
 /**
  * Repaints the rectangle blocks which are marked as 'dirty'.
  *
- * @see AddDirtyBlock
- *
- * @ingroup dirty
+ * @see SetDirtyBlocks
  */
 void DrawDirtyBlocks()
 {
@@ -1553,18 +1541,21 @@ void DrawDirtyBlocks()
 }
 
 /**
- * Extend the internal _invalid_rect rectangle to contain the rectangle
- * defined by the given parameters. Note the point (0,0) is top left.
+ * This function extends the internal _invalid_rect rectangle as it
+ * now contains the rectangle defined by the given parameters. Note
+ * the point (0,0) is top left.
  *
  * @param left The left edge of the rectangle
  * @param top The top edge of the rectangle
  * @param right The right edge of the rectangle
  * @param bottom The bottom edge of the rectangle
  * @see DrawDirtyBlocks
- * @ingroup dirty
  *
+ * @todo The name of the function should be called like @c AddDirtyBlock as
+ *       it neither set a dirty rect nor add several dirty rects although
+ *       the function name is in plural. (Progman)
  */
-void AddDirtyBlock(int left, int top, int right, int bottom)
+void SetDirtyBlocks(int left, int top, int right, int bottom)
 {
 	byte *b;
 	int width;
@@ -1609,7 +1600,7 @@ void AddDirtyBlock(int left, int top, int right, int bottom)
  */
 void MarkWholeScreenDirty()
 {
-	AddDirtyBlock(0, 0, _screen.width, _screen.height);
+	SetDirtyBlocks(0, 0, _screen.width, _screen.height);
 }
 
 /**
diff --git a/src/gfx_func.h b/src/gfx_func.h
index 0edbf722a1..0ccdabac3d 100644
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -131,7 +131,7 @@ Point GetCharPosInString(const char *str, const char *ch, FontSize start_fontsiz
 const char *GetCharAtPosition(const char *str, int x, FontSize start_fontsize = FS_NORMAL);
 
 void DrawDirtyBlocks();
-void AddDirtyBlock(int left, int top, int right, int bottom);
+void SetDirtyBlocks(int left, int top, int right, int bottom);
 void MarkWholeScreenDirty();
 
 void GfxInitPalettes();
diff --git a/src/news_gui.cpp b/src/news_gui.cpp
index 9993645c43..01b69677e3 100644
--- a/src/news_gui.cpp
+++ b/src/news_gui.cpp
@@ -571,7 +571,7 @@ private:
 		if (this->viewport != nullptr) this->viewport->top += newtop - this->top;
 		this->top = newtop;
 
-		AddDirtyBlock(this->left, mintop, this->left + this->width, maxtop + this->height);
+		SetDirtyBlocks(this->left, mintop, this->left + this->width, maxtop + this->height);
 	}
 
 	StringID GetCompanyMessageString() const
diff --git a/src/viewport.cpp b/src/viewport.cpp
index 28345db607..1c9dca1ef6 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -1886,7 +1886,7 @@ static void MarkViewportDirty(const ViewPort *vp, int left, int top, int right,
 
 	if (top >= vp->virtual_height) return;
 
-	AddDirtyBlock(
+	SetDirtyBlocks(
 		UnScaleByZoomLower(left, vp->zoom) + vp->left,
 		UnScaleByZoomLower(top, vp->zoom) + vp->top,
 		UnScaleByZoom(right, vp->zoom) + vp->left + 1,
diff --git a/src/widget.cpp b/src/widget.cpp
index 579b7efb64..eb683c4128 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -774,7 +774,7 @@ void NWidgetBase::SetDirty(const Window *w) const
 {
 	int abs_left = w->left + this->pos_x;
 	int abs_top = w->top + this->pos_y;
-	AddDirtyBlock(abs_left, abs_top, abs_left + this->current_x, abs_top + this->current_y);
+	SetDirtyBlocks(abs_left, abs_top, abs_left + this->current_x, abs_top + this->current_y);
 }
 
 /**
diff --git a/src/window.cpp b/src/window.cpp
index 9fea6d1026..f9f05d75a3 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -983,7 +983,7 @@ void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
  */
 void Window::SetDirty() const
 {
-	AddDirtyBlock(this->left, this->top, this->left + this->width, this->top + this->height);
+	SetDirtyBlocks(this->left, this->top, this->left + this->width, this->top + this->height);
 }
 
 /**
@@ -3493,7 +3493,7 @@ static int PositionWindow(Window *w, WindowClass clss, int setting)
 		default: w->left = 0; break;
 	}
 	if (w->viewport != nullptr) w->viewport->left += w->left - old_left;
-	AddDirtyBlock(0, w->top, _screen.width, w->top + w->height); // invalidate the whole row
+	SetDirtyBlocks(0, w->top, _screen.width, w->top + w->height); // invalidate the whole row
 	return w->left;
 }