diff --git a/modules/libjar/nsJAR.cpp b/modules/libjar/nsJAR.cpp
index 0c7955c6a832..15f84f7bb956 100644
--- a/modules/libjar/nsJAR.cpp
+++ b/modules/libjar/nsJAR.cpp
@@ -376,15 +376,8 @@ nsJAR::GetCertificatePrincipal(const char* aFilename, nsIPrincipal** aPrincipal)
     return NS_ERROR_NULL_POINTER;
   *aPrincipal = nsnull;
 
-  //-- Get the signature verifier service
-  nsresult rv;
-  nsCOMPtr<nsISignatureVerifier> verifier = 
-           do_GetService(SIGNATURE_VERIFIER_CONTRACTID, &rv);
-  if (NS_FAILED(rv)) // No signature verifier available
-    return NS_OK;
-
   //-- Parse the manifest
-  rv = ParseManifest(verifier);
+  nsresult rv = ParseManifest();
   if (NS_FAILED(rv)) return rv;
   if (mGlobalStatus == JAR_NO_MANIFEST)
     return NS_OK;
@@ -525,7 +518,7 @@ nsJAR::ReadLine(const char** src)
 #define JAR_SF_HEADER (const char*)"Signature-Version: 1.0"
 
 nsresult
-nsJAR::ParseManifest(nsISignatureVerifier* verifier)
+nsJAR::ParseManifest()
 {
   //-- Verification Step 1
   if (mParsedManifest)
@@ -612,6 +605,16 @@ nsJAR::ParseManifest(nsISignatureVerifier* verifier)
     return NS_OK;
   }
 
+  //-- Get the signature verifier service
+  nsCOMPtr<nsISignatureVerifier> verifier = 
+           do_GetService(SIGNATURE_VERIFIER_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) // No signature verifier available
+  {
+    mGlobalStatus = JAR_NO_MANIFEST;
+    mParsedManifest = PR_TRUE;
+    return NS_OK;
+  }
+
   //-- Verify that the signature file is a valid signature of the SF file
   PRInt32 verifyError;
   rv = verifier->VerifySignature(sigBuffer, sigLen, manifestBuffer, manifestLen, 
diff --git a/modules/libjar/nsJAR.h b/modules/libjar/nsJAR.h
index 4dd2210dc5d7..8129d97056c5 100644
--- a/modules/libjar/nsJAR.h
+++ b/modules/libjar/nsJAR.h
@@ -154,7 +154,7 @@ class nsJAR : public nsIZipReader, public nsIJAR
     //-- Private functions
     PRFileDesc* OpenFile();
 
-    nsresult ParseManifest(nsISignatureVerifier* verifier);
+    nsresult ParseManifest();
     void     ReportError(const char* aFilename, PRInt16 errorCode);
     nsresult LoadEntry(const char* aFilename, char** aBuf, 
                        PRUint32* aBufLen = nsnull);