diff --git a/tree.go b/tree.go
index af95bd4..faf5fdc 100644
--- a/tree.go
+++ b/tree.go
@@ -188,7 +188,7 @@
 
 			} else if i == len(path) { // Make node a (in-path) leaf
 				if n.handle != nil {
-					panic("a handle is already registered for path ''" + fullPath + "'")
+					panic("a handle is already registered for path '" + fullPath + "'")
 				}
 				n.handle = handle
 			}