diff --git a/src/frontends/qt/GuiFontMetrics.h b/src/frontends/qt/GuiFontMetrics.h
index 95b577cdf4..9c7ce89ae0 100644
--- a/src/frontends/qt/GuiFontMetrics.h
+++ b/src/frontends/qt/GuiFontMetrics.h
@@ -39,8 +39,6 @@ struct BreakAtKey
 	bool force;
 };
 
-static uint qHash(BreakAtKey const &);
-
 struct TextLayoutKey
 {
 	bool operator==(TextLayoutKey const & key) const {