diff --git a/src/wp-includes/class-wp-image-editor-gd.php b/src/wp-includes/class-wp-image-editor-gd.php
index be6e6f475f..79111bfc53 100644
--- a/src/wp-includes/class-wp-image-editor-gd.php
+++ b/src/wp-includes/class-wp-image-editor-gd.php
@@ -383,8 +383,15 @@ class WP_Image_Editor_GD extends WP_Image_Editor {
 			if ( function_exists('imageistruecolor') && ! imageistruecolor( $image ) )
 				imagetruecolortopalette( $image, false, imagecolorstotal( $image ) );
 
-			if ( ! $this->make_image( $filename, 'imagepng', array( $image, $filename ) ) )
+			/*
+			 * Invert the 1-100 quality scale and constrain it to 0-9,
+			 * as per imagepng()'s peculiar quality parameter.
+			 */
+			$compression_level = floor( ( 101 - $this->quality ) * 0.09 );
+
+			if ( ! $this->make_image( $filename, 'imagepng', array( $image, $filename, $compression_level ) ) ) {
 				return new WP_Error( 'image_save_error', __('Image Editor Save Failed') );
+			}
 		}
 		elseif ( 'image/jpeg' == $mime_type ) {
 			if ( ! $this->make_image( $filename, 'imagejpeg', array( $image, $filename, $this->quality ) ) )