diff --git a/src/test/perl/PostgresNode.pm b/src/test/perl/PostgresNode.pm
index 0914fdaa46..8c1b77376f 100644
--- a/src/test/perl/PostgresNode.pm
+++ b/src/test/perl/PostgresNode.pm
@@ -1512,15 +1512,19 @@ sub psql
 		}
 	};
 
+	# Note: on Windows, IPC::Run seems to convert \r\n to \n in program output
+	# if we're using native Perl, but not if we're using MSys Perl.  So do it
+	# by hand in the latter case, here and elsewhere.
+
 	if (defined $$stdout)
 	{
-		$$stdout =~ s/\r\n/\n/g if $TestLib::windows_os;
+		$$stdout =~ s/\r\n/\n/g if $Config{osname} eq 'msys';
 		chomp $$stdout;
 	}
 
 	if (defined $$stderr)
 	{
-		$$stderr =~ s/\r\n/\n/g if $TestLib::windows_os;
+		$$stderr =~ s/\r\n/\n/g if $Config{osname} eq 'msys';
 		chomp $$stderr;
 	}
 
@@ -1651,7 +1655,7 @@ sub poll_query_until
 	{
 		my $result = IPC::Run::run $cmd, '>', \$stdout, '2>', \$stderr;
 
-		$stdout =~ s/\r\n/\n/g if $TestLib::windows_os;
+		$stdout =~ s/\r\n/\n/g if $Config{osname} eq 'msys';
 		chomp($stdout);
 
 		if ($stdout eq $expected)
@@ -1667,7 +1671,7 @@ sub poll_query_until
 
 	# The query result didn't change in 180 seconds. Give up. Print the
 	# output from the last attempt, hopefully that's useful for debugging.
-	$stderr =~ s/\r\n/\n/g if $TestLib::windows_os;
+	$stderr =~ s/\r\n/\n/g if $Config{osname} eq 'msys';
 	chomp($stderr);
 	diag qq(poll_query_until timed out executing this query:
 $query
@@ -2112,8 +2116,8 @@ sub pg_recvlogical_upto
 		}
 	};
 
-	$stdout =~ s/\r\n/\n/g if $TestLib::windows_os;
-	$stderr =~ s/\r\n/\n/g if $TestLib::windows_os;
+	$stdout =~ s/\r\n/\n/g if $Config{osname} eq 'msys';
+	$stderr =~ s/\r\n/\n/g if $Config{osname} eq 'msys';
 
 	if (wantarray)
 	{