diff --git a/sci-visualization/labplot/files/labplot-2.11.1-missing-header.patch b/sci-visualization/labplot/files/labplot-2.11.1-missing-header.patch
new file mode 100644
index 000000000000..51fd699ed0e7
--- /dev/null
+++ b/sci-visualization/labplot/files/labplot-2.11.1-missing-header.patch
@@ -0,0 +1,24 @@
+From c2db2ec28aa8958f7041ae5cd03ddae9f44e5aa3 Mon Sep 17 00:00:00 2001
+From: Alexander Semke <alexander.semke@web.de>
+Date: Sun, 12 Oct 2025 13:54:57 +0200
+Subject: [PATCH] Added the missing include to fix the build.
+
+---
+ src/backend/worksheet/plots/cartesian/XYFourierFilterCurve.cpp | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/src/backend/worksheet/plots/cartesian/XYFourierFilterCurve.cpp b/src/backend/worksheet/plots/cartesian/XYFourierFilterCurve.cpp
+index 5957bb22ce..f6d0ed4b56 100644
+--- a/src/backend/worksheet/plots/cartesian/XYFourierFilterCurve.cpp
++++ b/src/backend/worksheet/plots/cartesian/XYFourierFilterCurve.cpp
+@@ -24,6 +24,7 @@ extern "C" {
+ #include "backend/nsl/nsl_sf_poly.h"
+ }
+ 
++#include <QElapsedTimer>
+ #include <QDebug> // qWarning()
+ #include <QIcon>
+ #include <QThreadPool>
+-- 
+GitLab
+
diff --git a/sci-visualization/labplot/labplot-2.11.1-r1.ebuild b/sci-visualization/labplot/labplot-2.11.1-r1.ebuild
index ff768b9734d7..acf66318b117 100644
--- a/sci-visualization/labplot/labplot-2.11.1-r1.ebuild
+++ b/sci-visualization/labplot/labplot-2.11.1-r1.ebuild
@@ -80,6 +80,7 @@ PATCHES=(
 	"${FILESDIR}/${P}-ods-buildfix.patch"
 	"${FILESDIR}/${P}-qtads-cmake-minreqver-3.16.patch" # bug #965103
 	"${FILESDIR}/${P}-qt-6.10.patch" # bug #966308
+	"${FILESDIR}/${P}-missing-header.patch" # bug #966438
 )
 
 src_prepare() {