diff --git a/libvips/foreign/svgload.c b/libvips/foreign/svgload.c
index 62c747de..3c864c09 100644
--- a/libvips/foreign/svgload.c
+++ b/libvips/foreign/svgload.c
@@ -467,11 +467,12 @@ vips_foreign_load_svg_is_a_buffer( const void *buf, size_t len )
 	 * <svg xmlns="http://www.w3.org/2000/svg" ...
 	 *
 	 * But there can be a doctype in there too. And case and whitespace can
-	 * vary a lot. And the <?xml can be missing. 
+	 * vary a lot. And the <?xml can be missing. And you can have a comment
+	 * before the <svg line.
 	 *
 	 * Simple rules:
 	 * - first 24 chars are plain ascii
-	 * - first 200 chars contain "<svg", upper or lower case.
+	 * - first 300 chars contain "<svg", upper or lower case.
 	 *
 	 * We could rsvg_handle_new_from_data() on the buffer, but that can be
 	 * horribly slow for large documents. 
@@ -482,7 +483,7 @@ vips_foreign_load_svg_is_a_buffer( const void *buf, size_t len )
 		if( !isascii( str[i] ) )
 			return( FALSE );
 
-	for( i = 0; i < 250 && i < len - 5; i++ )
+	for( i = 0; i < 300 && i < len - 5; i++ )
 		if( g_ascii_strncasecmp( str + i, "<svg", 4 ) == 0 )
 			return( TRUE );