Index: lldb/source/DataFormatters/FormatManager.cpp
===================================================================
--- lldb/source/DataFormatters/FormatManager.cpp
+++ lldb/source/DataFormatters/FormatManager.cpp
@@ -583,14 +583,19 @@
 
 LanguageCategory *
 FormatManager::GetCategoryForLanguage(lldb::LanguageType lang_type) {
-  std::lock_guard<std::recursive_mutex> guard(m_language_categories_mutex);
-  auto iter = m_language_categories_map.find(lang_type),
-       end = m_language_categories_map.end();
-  if (iter != end)
-    return iter->second.get();
+  {
+    std::lock_guard<std::recursive_mutex> guard(m_language_categories_mutex);
+    auto iter = m_language_categories_map.find(lang_type),
+         end = m_language_categories_map.end();
+    if (iter != end)
+      return iter->second.get();
+  }
   LanguageCategory *lang_category = new LanguageCategory(lang_type);
-  m_language_categories_map[lang_type] =
-      LanguageCategory::UniquePointer(lang_category);
+  {
+    std::lock_guard<std::recursive_mutex> guard(m_language_categories_mutex);
+    m_language_categories_map[lang_type] =
+        LanguageCategory::UniquePointer(lang_category);
+  }
   return lang_category;
 }
 
Index: lldb/source/DataFormatters/TypeCategoryMap.cpp
===================================================================
--- lldb/source/DataFormatters/TypeCategoryMap.cpp
+++ lldb/source/DataFormatters/TypeCategoryMap.cpp
@@ -25,8 +25,10 @@
 }
 
 void TypeCategoryMap::Add(KeyType name, const ValueSP &entry) {
-  std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
-  m_map[name] = entry;
+  {
+    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
+    m_map[name] = entry;
+  }
   if (listener)
     listener->Changed();
 }