diff --git a/shared_realm.cpp b/shared_realm.cpp
index 28bb81b6..d5a7257f 100644
--- a/shared_realm.cpp
+++ b/shared_realm.cpp
@@ -38,6 +38,7 @@ Realm::Config::Config(const Config& c)
 , read_only(c.read_only)
 , in_memory(c.in_memory)
 , cache(c.cache)
+, disable_format_upgrade(c.disable_format_upgrade)
 , encryption_key(c.encryption_key)
 , schema_version(c.schema_version)
 , migration_function(c.migration_function)
@@ -71,7 +72,7 @@ Realm::Realm(Config config)
             m_history = realm::make_client_history(m_config.path, m_config.encryption_key.data());
             SharedGroup::DurabilityLevel durability = m_config.in_memory ? SharedGroup::durability_MemOnly :
                                                                            SharedGroup::durability_Full;
-            m_shared_group = std::make_unique<SharedGroup>(*m_history, durability, m_config.encryption_key.data());
+            m_shared_group = std::make_unique<SharedGroup>(*m_history, durability, m_config.encryption_key.data(), !m_config.disable_format_upgrade);
         }
     }
     catch (util::File::PermissionDenied const& ex) {
@@ -92,6 +93,11 @@ Realm::Realm(Config config)
                                  "Realm file is currently open in another process "
                                  "which cannot share access with this process. All processes sharing a single file must be the same architecture.");
     }
+    catch (FileFormatUpgradeRequired const& ex) {
+        throw RealmFileException(RealmFileException::Kind::FormatUpgradeRequired, m_config.path,
+                                 "The Realm file format must be allowed to be upgraded "
+                                 "in order to proceed.");
+    }
 }
 
 Realm::~Realm() {
diff --git a/shared_realm.hpp b/shared_realm.hpp
index 67b4f3a5..97399f59 100644
--- a/shared_realm.hpp
+++ b/shared_realm.hpp
@@ -49,6 +49,7 @@ namespace realm {
             bool read_only = false;
             bool in_memory = false;
             bool cache = true;
+            bool disable_format_upgrade = false;
             std::vector<char> encryption_key;
 
             std::unique_ptr<Schema> schema;
@@ -162,6 +163,8 @@ namespace realm {
              process which cannot share with the current process due to an
              architecture mismatch. */
             IncompatibleLockFile,
+            /** Thrown if the file needs to be upgraded to a new format, but upgrades have been explicitly disabled. */
+            FormatUpgradeRequired,
         };
         RealmFileException(Kind kind, std::string path, std::string message) :
             std::runtime_error(std::move(message)), m_kind(kind), m_path(std::move(path)) {}