diff --git a/lib/Test/MockFile.pm b/lib/Test/MockFile.pm
index f2a3f57..84ccb85 100644
--- a/lib/Test/MockFile.pm
+++ b/lib/Test/MockFile.pm
@@ -3290,6 +3290,7 @@ sub __rmdir (_) {
     # Core sometimes warns: 'Use of uninitialized value $_ in rmdir'
     if ( !defined $file ) {
         carp('Use of uninitialized value in rmdir');
+        $! = ENOENT;
         return 0;
     }
 
diff --git a/t/rmdir.t b/t/rmdir.t
index 0191e20..30eec9f 100644
--- a/t/rmdir.t
+++ b/t/rmdir.t
@@ -48,8 +48,10 @@ subtest "undef rmdir" => sub {
     is( $returns, 0, " - returns 0" );
 
     local $_;
+    $! = 0;
     like( warning { $returns = rmdir(undef) }, qr/^Use of uninitialized value in rmdir at.+\n$/, "REAL mkdir when undef is passed as the directory." );
-    is( $returns, 0, " - returns 0" );
+    is( $returns, 0,      " - returns 0" );
+    is( $! + 0,   ENOENT, " - \$! is ENOENT" );
 };
 
 subtest "rmdir existing file" => sub {