diff --git a/apps/theming/lib/IconBuilder.php b/apps/theming/lib/IconBuilder.php
index 844146724a51f..e7e83a0b4c04b 100644
--- a/apps/theming/lib/IconBuilder.php
+++ b/apps/theming/lib/IconBuilder.php
@@ -124,9 +124,10 @@ public function renderAppIcon($app, $size) {
 		$color = $this->themingDefaults->getColorPrimary();
 
 		// generate background image with rounded corners
+		$cornerRadius = 0.2 * $size;
 		$background = '<?xml version="1.0" encoding="UTF-8"?>' .
-			'<svg xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:cc="http://creativecommons.org/ns#" width="512" height="512" xmlns:xlink="http://www.w3.org/1999/xlink">' .
-			'<rect x="0" y="0" rx="100" ry="100" width="512" height="512" style="fill:' . $color . ';" />' .
+			'<svg xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:cc="http://creativecommons.org/ns#" width="' . $size . '" height="' . $size . '" xmlns:xlink="http://www.w3.org/1999/xlink">' .
+			'<rect x="0" y="0" rx="' . $cornerRadius . '" ry="' . $cornerRadius . '" width="' . $size. '" height="' . $size . '" style="fill:' . $color . ';" />' .
 			'</svg>';
 		// resize svg magic as this seems broken in Imagemagick
 		if ($mime === 'image/svg+xml' || substr($appIconContent, 0, 4) === '<svg') {
@@ -136,22 +137,17 @@ public function renderAppIcon($app, $size) {
 				$svg = $appIconContent;
 			}
 			$tmp = new Imagick();
+			$tmp->setBackgroundColor(new ImagickPixel('transparent'));
+			$tmp->setResolution(72, 72);
 			$tmp->readImageBlob($svg);
 			$x = $tmp->getImageWidth();
 			$y = $tmp->getImageHeight();
-			$res = $tmp->getImageResolution();
 			$tmp->destroy();
 
-			if ($x > $y) {
-				$max = $x;
-			} else {
-				$max = $y;
-			}
-
 			// convert svg to resized image
 			$appIconFile = new Imagick();
-			$resX = (int)(512 * $res['x'] / $max * 2.53);
-			$resY = (int)(512 * $res['y'] / $max * 2.53);
+			$resX = (int)(72 * $size / $x);
+			$resY = (int)(72 * $size / $y);
 			$appIconFile->setResolution($resX, $resY);
 			$appIconFile->setBackgroundColor(new ImagickPixel('transparent'));
 			$appIconFile->readImageBlob($svg);
@@ -166,22 +162,21 @@ public function renderAppIcon($app, $size) {
 			) {
 				$appIconFile->negateImage(false);
 			}
-			$appIconFile->scaleImage(512, 512, true);
 		} else {
 			$appIconFile = new Imagick();
 			$appIconFile->setBackgroundColor(new ImagickPixel('transparent'));
 			$appIconFile->readImageBlob($appIconContent);
-			$appIconFile->scaleImage(512, 512, true);
 		}
 		// offset for icon positioning
-		$border_w = (int)($appIconFile->getImageWidth() * 0.05);
-		$border_h = (int)($appIconFile->getImageHeight() * 0.05);
+		$padding = 0.15;
+		$border_w = (int)($appIconFile->getImageWidth() * $padding);
+		$border_h = (int)($appIconFile->getImageHeight() * $padding);
 		$innerWidth = ($appIconFile->getImageWidth() - $border_w * 2);
 		$innerHeight = ($appIconFile->getImageHeight() - $border_h * 2);
 		$appIconFile->adaptiveResizeImage($innerWidth, $innerHeight);
 		// center icon
-		$offset_w = (int)(512 / 2 - $innerWidth / 2);
-		$offset_h = (int)(512 / 2 - $innerHeight / 2);
+		$offset_w = (int)($size / 2 - $innerWidth / 2);
+		$offset_h = (int)($size / 2 - $innerHeight / 2);
 
 		$finalIconFile = new Imagick();
 		$finalIconFile->setBackgroundColor(new ImagickPixel('transparent'));