diff --git a/Gemfile.lock b/Gemfile.lock
index c419a75..94a2284 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    activerecord-pg-extensions (0.5.2)
+    activerecord-pg-extensions (0.5.3)
       activerecord (~> 7.0.0)
       railties (~> 7.0.0)
 
@@ -157,4 +157,4 @@ DEPENDENCIES
   rubocop-rspec (~> 2.3)
 
 BUNDLED WITH
-   2.2.17
+   2.4.19
diff --git a/gemfiles/rails_7.0.gemfile.lock b/gemfiles/rails_7.0.gemfile.lock
index 6a091bc..ab84a4e 100644
--- a/gemfiles/rails_7.0.gemfile.lock
+++ b/gemfiles/rails_7.0.gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    activerecord-pg-extensions (0.5.1)
+    activerecord-pg-extensions (0.5.3)
       activerecord (~> 7.0.0)
       railties (~> 7.0.0)
 
diff --git a/lib/active_record/pg_extensions/postgresql_adapter.rb b/lib/active_record/pg_extensions/postgresql_adapter.rb
index 551cbb9..17651ae 100644
--- a/lib/active_record/pg_extensions/postgresql_adapter.rb
+++ b/lib/active_record/pg_extensions/postgresql_adapter.rb
@@ -10,7 +10,7 @@ module PostgreSQLAdapter
       # see https://www.postgresql.org/docs/current/sql-set-constraints.html
       def set_constraints(deferred, *constraints)
         raise ArgumentError, "deferred must be :deferred or :immediate" unless %i[deferred
-                                                                                  immediate].include?(deferred)
+                                                                                  immediate].include?(deferred.to_sym)
 
         constraints = constraints.map { |c| quote_table_name(c) }.join(", ")
         constraints = "ALL" if constraints.empty?
diff --git a/lib/active_record/pg_extensions/version.rb b/lib/active_record/pg_extensions/version.rb
index 62a34d8..5c46ac2 100644
--- a/lib/active_record/pg_extensions/version.rb
+++ b/lib/active_record/pg_extensions/version.rb
@@ -2,6 +2,6 @@
 
 module ActiveRecord
   module PGExtensions
-    VERSION = "0.5.2"
+    VERSION = "0.5.3"
   end
 end
diff --git a/spec/postgresql_adapter_spec.rb b/spec/postgresql_adapter_spec.rb
index 07c6cab..5c44bc1 100644
--- a/spec/postgresql_adapter_spec.rb
+++ b/spec/postgresql_adapter_spec.rb
@@ -14,6 +14,11 @@
       expect { connection.set_constraints("garbage") }.to raise_error(ArgumentError)
     end
 
+    it "allows string arguments" do
+      expect { connection.set_constraints("deferred") }.not_to raise_error(ArgumentError)
+      expect { connection.set_constraints("immediate") }.not_to raise_error(ArgumentError)
+    end
+
     it "defaults to all" do
       connection.set_constraints(:deferred)
       expect(connection.executed_statements).to eq ["SET CONSTRAINTS ALL DEFERRED"]