diff --git a/org/openslide/OpenSlide.java b/org/openslide/OpenSlide.java
index 9e6e88f..6f96133 100644
--- a/org/openslide/OpenSlide.java
+++ b/org/openslide/OpenSlide.java
@@ -99,7 +99,8 @@ public static String detectVendor(File file) {
     }
 
     public OpenSlide(File file) throws IOException {
-        if (!file.exists()) {
+        // allow opening the synthetic slide
+        if (!file.exists() && !file.getPath().equals("")) {
             throw new FileNotFoundException(file.toString());
         }