diff --git a/pdf/src/previews.js b/pdf/src/previews.js
index f288b3c5dc..eef90f273b 100644
--- a/pdf/src/previews.js
+++ b/pdf/src/previews.js
@@ -40,6 +40,7 @@
     function(window, undefined) {
 
         function StampAnnotPreviewManager() {
+            this.canvasHeight = 28;
         }
 
         StampAnnotPreviewManager.prototype.clear = function() {
@@ -94,7 +95,9 @@
 			let pxWidth = oTextDrawer.Width * g_dKoef_mm_to_pix;
             let pxHeight = oTextDrawer.Height * g_dKoef_mm_to_pix;
 
-			let canvas		= this.createCanvas(pxWidth, pxHeight);
+            let canvasWidth = pxWidth * this.canvasHeight / pxHeight;
+
+			let canvas		= this.createCanvas(canvasWidth, this.canvasHeight);
             let ctx			= canvas.getContext('2d');
             let graphics	= new AscCommon.CGraphics();