diff --git a/dom/indexedDB/IDBObjectStore.cpp b/dom/indexedDB/IDBObjectStore.cpp
index 937048162e00..994e08b0a108 100644
--- a/dom/indexedDB/IDBObjectStore.cpp
+++ b/dom/indexedDB/IDBObjectStore.cpp
@@ -1109,8 +1109,8 @@ IDBObjectStore::AddOrPut(const jsval& aValue,
     return rv;
   }
 
-  // Put requires a key.
-  if (aOverwrite && key.IsUnset()) {
+  // Put requires a key, unless this is an autoIncrementing objectStore.
+  if (aOverwrite && !mAutoIncrement && key.IsUnset()) {
     return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
   }
 
@@ -1793,7 +1793,7 @@ AddHelper::DoDatabaseWork(mozIStorageConnection* aConnection)
   }
 
   // If we are supposed to generate a key, get the new id.
-  if (autoIncrement && !mOverwrite) {
+  if (autoIncrement && !mayOverwrite) {
 #ifdef DEBUG
     PRInt64 oldKey = unsetKey ? 0 : mKey.ToInteger();
 #endif
diff --git a/dom/indexedDB/test/test_key_requirements.html b/dom/indexedDB/test/test_key_requirements.html
index 72deede325b9..e057d4177466 100644
--- a/dom/indexedDB/test/test_key_requirements.html
+++ b/dom/indexedDB/test/test_key_requirements.html
@@ -61,18 +61,18 @@
 
       try {
         objectStore.put({});
-        ok(false, "put with no key should throw!");
+        ok(true, "put with no key should not throw with autoIncrement!");
       }
       catch (e) {
-        ok(true, "put with no key threw");
+        ok(false, "put with no key threw with autoIncrement");
       }
 
       try {
         objectStore.put({});
-        ok(false, "put with no key should throw!");
+        ok(true, "put with no key should not throw with autoIncrement!");
       }
       catch (e) {
-        ok(true, "put with no key threw");
+        ok(false, "put with no key threw with autoIncrement");
       }
 
       try {
@@ -247,18 +247,18 @@
 
       try {
         objectStore.put({});
-        ok(false, "put with no key should throw!");
+        ok(true, "put with no key should not throw with autoIncrement!");
       }
       catch (e) {
-        ok(true, "put with no key threw");
+        ok(false, "put with no key threw with autoIncrement");
       }
 
       try {
         objectStore.put({});
-        ok(false, "put with no key should throw!");
+        ok(true, "put with no key should not throw with autoIncrement!");
       }
       catch (e) {
-        ok(true, "put with no key threw");
+        ok(false, "put with no key threw with autoIncrement");
       }
 
       try {
diff --git a/dom/indexedDB/test/test_put_get_values_autoIncrement.html b/dom/indexedDB/test/test_put_get_values_autoIncrement.html
index 2ee8d5204c18..48fde0445850 100644
--- a/dom/indexedDB/test/test_put_get_values_autoIncrement.html
+++ b/dom/indexedDB/test/test_put_get_values_autoIncrement.html
@@ -29,7 +29,7 @@
       let objectStore = db.createObjectStore(objectStoreName,
                                              { autoIncrement: 1 });
 
-      request = objectStore.add(testString.value);
+      request = objectStore.put(testString.value);
       request.onerror = errorHandler;
       request.onsuccess = function(event) {
         testString.key = event.target.result;
@@ -40,7 +40,7 @@
         };
       };
 
-      request = objectStore.add(testInt.value);
+      request = objectStore.put(testInt.value);
       request.onerror = errorHandler;
       request.onsuccess = function(event) {
         testInt.key = event.target.result;