diff --git a/src/gfx.cpp b/src/gfx.cpp
index 459a236913..52b68bfff9 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -1718,8 +1718,8 @@ void DrawDirtyBlocks()
 	_gfx_draw_active = false;
 	++_dirty_block_colour;
 
-	extern void ClearViewPortCaches();
-	ClearViewPortCaches();
+	extern void ClearViewportCaches();
+	ClearViewportCaches();
 }
 
 void UnsetDirtyBlocks(int left, int top, int right, int bottom)
diff --git a/src/screenshot.cpp b/src/screenshot.cpp
index 02104bc5d4..cf6b9f40e2 100644
--- a/src/screenshot.cpp
+++ b/src/screenshot.cpp
@@ -675,7 +675,7 @@ static void LargeWorldCallback(void *userdata, void *buf, uint y, uint pitch, ui
 	_screen = old_screen;
 	_screen_disable_anim = old_disable_anim;
 
-	ClearViewPortCache(vp);
+	ClearViewportCache(vp);
 }
 
 /**
diff --git a/src/viewport.cpp b/src/viewport.cpp
index eaa628ba63..8e8ba63633 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -336,7 +336,7 @@ static Point MapXYZToViewport(const Viewport *vp, int x, int y, int z)
 	return p;
 }
 
-void ClearViewPortCache(Viewport *vp)
+void ClearViewportCache(Viewport *vp)
 {
 	if (vp->zoom >= ZOOM_LVL_DRAW_MAP) {
 		memset(vp->map_draw_vehicles_cache.done_hash_bits, 0, sizeof(vp->map_draw_vehicles_cache.done_hash_bits));
@@ -344,10 +344,10 @@ void ClearViewPortCache(Viewport *vp)
 	}
 }
 
-void ClearViewPortCaches()
+void ClearViewportCaches()
 {
 	for (Viewport *vp : _viewport_window_cache) {
-		ClearViewPortCache(vp);
+		ClearViewportCache(vp);
 	}
 }
 
@@ -680,7 +680,7 @@ static void SetViewportPosition(Window *w, int x, int y, bool force_update_overl
 		if (height > 0 && (_vp_move_offs.x != 0 || _vp_move_offs.y != 0)) {
 			SCOPE_INFO_FMT([&], "DoSetViewportPosition: %d, %d, %d, %d, %d, %d, %s", left, top, width, height, _vp_move_offs.x, _vp_move_offs.y, scope_dumper().WindowInfo(w));
 			DoSetViewportPosition((Window *) w->z_front, left, top, width, height);
-			ClearViewPortCache(w->viewport);
+			ClearViewportCache(w->viewport);
 		}
 	}
 }
diff --git a/src/viewport_func.h b/src/viewport_func.h
index 3ce9ef82d2..15485316ff 100644
--- a/src/viewport_func.h
+++ b/src/viewport_func.h
@@ -23,8 +23,8 @@ static const int TILE_HEIGHT_STEP = 50; ///< One Z unit tile height difference i
 
 void SetSelectionRed(bool);
 
-void ClearViewPortCache(Viewport *vp);
-void ClearViewPortCaches();
+void ClearViewportCache(Viewport *vp);
+void ClearViewportCaches();
 void DeleteWindowViewport(Window *w);
 void InitializeWindowViewport(Window *w, int x, int y, int width, int height, uint32 follow_flags, ZoomLevel zoom);
 Viewport *IsPtInWindowViewport(const Window *w, int x, int y);