diff --git a/src/platform/qt/GIFView.cpp b/src/platform/qt/GIFView.cpp
index 02c3b0f02..a71a4b81b 100644
--- a/src/platform/qt/GIFView.cpp
+++ b/src/platform/qt/GIFView.cpp
@@ -25,6 +25,8 @@ GIFView::GIFView(QWidget* parent)
 
 	connect(m_ui.selectFile, &QAbstractButton::clicked, this, &GIFView::selectFile);
 	connect(m_ui.filename, &QLineEdit::textChanged, this, &GIFView::setFilename);
+	connect(m_ui.fmtGif, &QAbstractButton::clicked, this, &GIFView::changeExtension);
+	connect(m_ui.fmtApng, &QAbstractButton::clicked, this, &GIFView::changeExtension);
 
 	FFmpegEncoderInit(&m_encoder);
 	FFmpegEncoderSetAudio(&m_encoder, nullptr, 0);
@@ -92,4 +94,21 @@ void GIFView::setFilename(const QString& filename) {
 	}
 }
 
+void GIFView::changeExtension() {
+	if (m_filename.isEmpty()) {
+		return;
+	}
+	QString filename = m_filename;
+	int index = m_filename.lastIndexOf(".");
+	if (index >= 0) {
+		filename.truncate(index);
+	}
+	if (m_ui.fmtGif->isChecked()) {
+		filename += ".gif";
+	} else if (m_ui.fmtApng->isChecked()) {
+		filename += ".png";
+	}
+	m_ui.filename->setText(filename);
+}
+
 #endif
diff --git a/src/platform/qt/GIFView.h b/src/platform/qt/GIFView.h
index fc4ebd1a3..37f71fd93 100644
--- a/src/platform/qt/GIFView.h
+++ b/src/platform/qt/GIFView.h
@@ -41,6 +41,7 @@ signals:
 private slots:
 	void selectFile();
 	void setFilename(const QString&);
+	void changeExtension();
 
 private:
 	Ui::GIFView m_ui;