diff --git a/lib/pg.rb b/lib/pg.rb
index 73f2f894c..557f81728 100644
--- a/lib/pg.rb
+++ b/lib/pg.rb
@@ -21,6 +21,7 @@ module PG
 			POSTGRESQL_LIB_PATH = false
 		end
 	end
+	POSTGRESQL_LIB_PATH.freeze
 
 	add_dll_path = proc do |path, &block|
 		if RUBY_PLATFORM =~/(mswin|mingw)/i && path
diff --git a/lib/pg/version.rb b/lib/pg/version.rb
index 579dbe2b8..d37ddd956 100644
--- a/lib/pg/version.rb
+++ b/lib/pg/version.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module PG
 	# Library version
 	VERSION = '1.6.1'
diff --git a/spec/pg_spec.rb b/spec/pg_spec.rb
index dc7b3e2b4..b24d3c1bf 100644
--- a/spec/pg_spec.rb
+++ b/spec/pg_spec.rb
@@ -57,4 +57,14 @@
 
 		expect( bres ).to eq( 55 )
 	end
+
+	it "should provide constants in a Ractor", :ractor do
+		vals = Ractor.new(@conninfo) do |conninfo|
+			[PG.library_version, PG.version_string, PG.threadsafe?, PG::VERSION, PG::POSTGRESQL_LIB_PATH]
+		end.value
+
+		expect( vals ).to eq(
+			[PG.library_version, PG.version_string, PG.threadsafe?, PG::VERSION, PG::POSTGRESQL_LIB_PATH]
+		)
+	end
 end