diff --git a/sources/exportdialog.cpp b/sources/exportdialog.cpp
index 552c24045..9d171ad8a 100644
--- a/sources/exportdialog.cpp
+++ b/sources/exportdialog.cpp
@@ -868,7 +868,25 @@ void ExportDialog::slot_changeFilesExtension(bool force_extension) {
 	// recupere le format a utiliser (acronyme et extension)
 	QString format_acronym = epw -> exportProperties().format;
 	QString format_extension = "." + format_acronym.toLower();
-	
+
+	// set maximum width / height according specifications of export-type
+	if (format_extension == ".bmp") {
+		foreach (auto line, diagram_lines_.values() ) {
+			line->width ->setRange(1, BMPmaxSize);
+			line->height->setRange(1, BMPmaxSize);
+		}
+	} else if (format_extension == ".jpg") {
+		foreach (auto line, diagram_lines_.values() ) {
+			line->width ->setRange(1, JPGmaxSize);
+			line->height->setRange(1, JPGmaxSize);
+		}
+	} else {
+		foreach (auto line, diagram_lines_.values() ) {
+			line->width ->setRange(1, GeneralMaxSize);
+			line->height->setRange(1, GeneralMaxSize);
+		}
+	}
+
 	// parcourt les schemas a exporter
 	foreach(ExportDiagramLine *diagram_line, diagram_lines_.values()) {
 		QString diagram_filename = diagram_line -> file_name -> text();
@@ -1008,16 +1026,16 @@ ExportDialog::ExportDiagramLine::ExportDiagramLine(Diagram *dia, QSize diagram_s
 	file_name -> setMinimumWidth(280);
 	
 	width = new QSpinBox();
-	width -> setRange(1, 100000);
+	width -> setRange(1, GeneralMaxSize);
 	width -> setSuffix(tr("px"));
 	width -> setValue(diagram_size.width());
 	
 	height = new QSpinBox();
-	height -> setRange(1, 100000);
+	height -> setRange(1, GeneralMaxSize);
 	height -> setSuffix(tr("px"));
 	height -> setValue(diagram_size.height());
 	
-	x_label = new QLabel("*");
+	x_label = new QLabel("×");
 	
 	keep_ratio = new QPushButton();
 	keep_ratio -> setCheckable(true);
diff --git a/sources/exportdialog.h b/sources/exportdialog.h
index b0b19602a..31bef13f3 100644
--- a/sources/exportdialog.h
+++ b/sources/exportdialog.h
@@ -79,6 +79,11 @@ class ExportDialog : public QDialog {
 	QSignalMapper *reset_mapper_;
 	QSignalMapper *clipboard_mapper_;
 	
+	// constants for exporting images:
+	static const int BMPmaxSize     =  32767;
+	static const int JPGmaxSize     =  65535;
+	static const int GeneralMaxSize = 100000;
+	
 	// project whose diagrams are to be exported
 	QETProject *project_;