diff --git a/lib/pg/connection.rb b/lib/pg/connection.rb
index 01eb0c2cd..bf409eea3 100755
--- a/lib/pg/connection.rb
+++ b/lib/pg/connection.rb
@@ -47,7 +47,7 @@ def self::parse_connect_args( *args )
 
 		if args.length == 1
 			case args.first
-			when URI, URI.regexp
+			when URI, /\A#{URI.regexp}\z/
 				uri = URI(args.first)
 				options.merge!( Hash[URI.decode_www_form( uri.query )] ) if uri.query
 			when /=/
diff --git a/spec/pg/connection_spec.rb b/spec/pg/connection_spec.rb
index d0556730a..c07d13968 100755
--- a/spec/pg/connection_spec.rb
+++ b/spec/pg/connection_spec.rb
@@ -118,6 +118,19 @@
 		expect( described_class.parse_connect_args ).to eq( '' )
 	end
 
+	it "connects successfully with connection string" do
+		conninfo_with_colon_in_password = "host=localhost user=a port=555 dbname=test password=a:a"
+
+		string = described_class.parse_connect_args( conninfo_with_colon_in_password )
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{(^|\s)user=a} )
+		expect( string ).to match( %r{(^|\s)password=a:a} )
+		expect( string ).to match( %r{(^|\s)host=localhost} )
+		expect( string ).to match( %r{(^|\s)port=555} )
+		expect( string ).to match( %r{(^|\s)dbname=test} )
+	end
+
 	it "connects successfully with connection string" do
 		tmpconn = described_class.connect( @conninfo )
 		expect( tmpconn.status ).to eq( PG::CONNECTION_OK )