diff --git a/src/linkgraph/linkgraph_gui.cpp b/src/linkgraph/linkgraph_gui.cpp
index d0e1d09b44..3cd456160c 100644
--- a/src/linkgraph/linkgraph_gui.cpp
+++ b/src/linkgraph/linkgraph_gui.cpp
@@ -112,6 +112,7 @@ void LinkGraphOverlay::MarkStationViewportLinksDirty(const Station *st)
 void LinkGraphOverlay::RebuildCache(bool incremental)
 {
 	if (!incremental) {
+		this->dirty = false;
 		this->cached_links.clear();
 		this->cached_stations.clear();
 		this->last_update_number = GetWindowUpdateNumber();
@@ -387,7 +388,6 @@ void LinkGraphOverlay::PrepareDraw()
 {
 	if (this->dirty) {
 		this->RebuildCache();
-		this->dirty = false;
 	}
 	if (this->last_update_number != GetWindowUpdateNumber()) {
 		this->last_update_number = GetWindowUpdateNumber();
diff --git a/src/linkgraph/linkgraph_gui.h b/src/linkgraph/linkgraph_gui.h
index cf6cf25195..94e1abe25e 100644
--- a/src/linkgraph/linkgraph_gui.h
+++ b/src/linkgraph/linkgraph_gui.h
@@ -70,7 +70,7 @@ public:
 	 * @param scale Desired thickness of lines and size of station dots.
 	 */
 	LinkGraphOverlay(Window *w, uint wid, CargoTypes cargo_mask, uint32 company_mask, uint scale) :
-			window(w), widget_id(wid), cargo_mask(cargo_mask), company_mask(company_mask), scale(scale)
+			window(w), widget_id(wid), cargo_mask(cargo_mask), company_mask(company_mask), scale(scale), dirty(true)
 	{}
 
 	void RebuildCache(bool incremental = false);