diff --git a/mozilla/modules/libreg/xpcom/nsRegistry.cpp b/mozilla/modules/libreg/xpcom/nsRegistry.cpp
index f72d8a42ca4..e84820c5cef 100644
--- a/mozilla/modules/libreg/xpcom/nsRegistry.cpp
+++ b/mozilla/modules/libreg/xpcom/nsRegistry.cpp
@@ -712,6 +712,7 @@ NS_IMETHODIMP nsRegistry::GetStringUTF8( nsRegistryKey baseKey, const char *path
     {
         // Convert status.
         rv = regerr2nsresult( err );
+        NS_ASSERTION(NS_FAILED(rv), "returning success code on failure");
     }
 
    return rv;
diff --git a/mozilla/xpcom/components/nsRegistry.cpp b/mozilla/xpcom/components/nsRegistry.cpp
index f72d8a42ca4..e84820c5cef 100644
--- a/mozilla/xpcom/components/nsRegistry.cpp
+++ b/mozilla/xpcom/components/nsRegistry.cpp
@@ -712,6 +712,7 @@ NS_IMETHODIMP nsRegistry::GetStringUTF8( nsRegistryKey baseKey, const char *path
     {
         // Convert status.
         rv = regerr2nsresult( err );
+        NS_ASSERTION(NS_FAILED(rv), "returning success code on failure");
     }
 
    return rv;