diff --git a/lib/raster.js b/lib/raster.js
index 88411b2..20b0014 100644
--- a/lib/raster.js
+++ b/lib/raster.js
@@ -51,7 +51,7 @@ function Raster(filepath) {
   var ratio = Math.abs(geotransform[1] / geotransform[5]);
 
   if (geotransform[1] <= 0 || geotransform[5] >= 0) throw invalid('Invalid raster: Invalid pixelsize in geotransform array');
-  if (ratio < 0.5 || ratio > 2) throw invalid('Invalid raster: Invalid pixelsize in geotransform array');
+  if (ratio < 0.5 || ratio > 5) throw invalid('Invalid raster: Invalid pixelsize in geotransform array');
   if (geotransform[2] !== 0 || geotransform[4] !== 0) throw invalid('Invalid raster: Invalid rotation value in geotransform array');
 
   this.details.pixelSize = [geotransform[1], geotransform[5]];