diff --git a/libraries/base/tests/IO/all.T b/libraries/base/tests/IO/all.T
index fe8faa0ce058d9b663f848e1f4eba6a45b91429c..61011d23042bb8435e22c7318b920da547819e43 100644
--- a/libraries/base/tests/IO/all.T
+++ b/libraries/base/tests/IO/all.T
@@ -145,7 +145,8 @@ test('encoding001',
 test('encoding002', normal, compile_and_run, [''])
 test('encoding003', normal, compile_and_run, [''])
 test('encoding004', normal, compile_and_run, [''])
-test('encoding005', normal, compile_and_run, [''])
+test('encoding005', when(opsys('mingw32'), expect_broken(10623)),
+     compile_and_run, [''])
 
 test('environment001',
      [extra_clean(['environment001'])],