diff --git a/core/src/main/java/org/jruby/runtime/load/LibrarySearcher.java b/core/src/main/java/org/jruby/runtime/load/LibrarySearcher.java
index 1256d2c9a66d..e963d492be03 100644
--- a/core/src/main/java/org/jruby/runtime/load/LibrarySearcher.java
+++ b/core/src/main/java/org/jruby/runtime/load/LibrarySearcher.java
@@ -331,7 +331,7 @@ public CharSequence subSequence(int start, int end) {
 
         @Override
         public String toString() {
-            return str.substring(beg, beg + len);
+            return "StringWrapper(" + (str == null ? "" : str.substring(beg, beg + len)) + ")";
         }
 
         @Override