diff --git a/src/rpc/object_storage.cc b/src/rpc/object_storage.cc
index 9cee97d4..b79b783a 100644
--- a/src/rpc/object_storage.cc
+++ b/src/rpc/object_storage.cc
@@ -64,8 +64,12 @@ object_storage::insert(const char* key_data, uint32_t key_size, const torrent::O
   if (std::find(key_data, key_data + key_size, '\0') != key_data + key_size)
     throw torrent::input_error("Found nul-char in string.");
 
-  // Check for size > key_size.
-  // Check for empty string.
+  // key_type turns a key this long into the empty key.
+  if (key_size >= object_storage::key_size)
+    throw torrent::input_error("Key is too long.");
+
+  if (key_size == 0)
+    throw torrent::input_error("Key is empty.");
 
   bool use_raw = false;
   torrent::Object object;
diff --git a/test/rpc/test_object_storage.cc b/test/rpc/test_object_storage.cc
index aef2e143..3284c7ba 100644
--- a/test/rpc/test_object_storage.cc
+++ b/test/rpc/test_object_storage.cc
@@ -49,6 +49,17 @@ TestObjectStorage::test_validate_keys() {
   torrent::raw_string raw_string_4("test_4\0foo", 10);
 
   ASSERT_CATCH_INPUT_ERROR( { m_storage.insert(raw_string_4, torrent::Object("a"), rpc::object_storage::flag_string_type); } );
+  ASSERT_CATCH_INPUT_ERROR( { m_storage.insert_str("", torrent::Object("a"), rpc::object_storage::flag_string_type); } );
+
+  std::string key_max(rpc::object_storage::key_size - 1, 'k');
+
+  CPPUNIT_ASSERT(m_storage.insert_str(key_max, torrent::Object("a"), rpc::object_storage::flag_string_type)->first == key_max);
+  ASSERT_CATCH_INPUT_ERROR( { m_storage.insert_str(key_max + 'k', torrent::Object("a"), rpc::object_storage::flag_string_type); } );
+
+  // The over-long key must not have been stored as the empty key.
+  CPPUNIT_ASSERT(m_storage.find_raw_string(torrent::raw_string::from_c_str("")) == m_storage.end());
+
+  m_storage.clear();
 }
 
 // And test many other bad/good string combos.