diff --git a/xpcom/io/nsLocalFileOS2.cpp b/xpcom/io/nsLocalFileOS2.cpp
index ac79cf53b905..8b8072bde075 100644
--- a/xpcom/io/nsLocalFileOS2.cpp
+++ b/xpcom/io/nsLocalFileOS2.cpp
@@ -2345,6 +2345,27 @@ nsLocalFile::GetTarget(nsAString &_retval)
     return rv;
 }
 
+// nsIHashable
+
+NS_IMETHODIMP
+nsLocalFile::Equals(nsIHashable* aOther, PRBool *aResult)
+{
+    nsCOMPtr<nsIFile> otherfile(do_QueryInterface(aOther));
+    if (!otherfile) {
+        *aResult = PR_FALSE;
+        return NS_OK;
+    }
+
+    return Equals(otherfile, aResult);
+}
+
+NS_IMETHODIMP
+nsLocalFile::GetHashCode(PRUint32 *aResult)
+{
+    *aResult = nsCRT::HashCode(mWorkingPath.get());
+    return NS_OK;
+}
+
 nsresult
 NS_NewLocalFile(const nsAString &path, PRBool followLinks, nsILocalFile* *result)
 {
diff --git a/xpcom/io/nsLocalFileOS2.h b/xpcom/io/nsLocalFileOS2.h
index 7b9bcd5b0576..2649ec950162 100644
--- a/xpcom/io/nsLocalFileOS2.h
+++ b/xpcom/io/nsLocalFileOS2.h
@@ -55,6 +55,7 @@
 #include "nsIFile.h"
 #include "nsIFactory.h"
 #include "nsILocalFileOS2.h"
+#include "nsIHashable.h"
 
 #define INCL_DOSFILEMGR
 #define INCL_DOSERRORS
@@ -70,7 +71,8 @@
 
 class TypeEaEnumerator;
 
-class NS_COM nsLocalFile : public nsILocalFileOS2
+class NS_COM nsLocalFile : public nsILocalFileOS2,
+                                   public nsIHashable
 {
 public:
     NS_DEFINE_STATIC_CID_ACCESSOR(NS_LOCAL_FILE_CID)
@@ -91,6 +93,9 @@ public:
     // nsILocalFileOS2 interface
     NS_DECL_NSILOCALFILEOS2
 
+    // nsIHashable interface
+    NS_DECL_NSIHASHABLE
+
 public:
     static void GlobalInit();
     static void GlobalShutdown();