diff --git a/tests/strings/strings.cpp b/tests/strings/strings.cpp
index b751de07f7..84569f043f 100644
--- a/tests/strings/strings.cpp
+++ b/tests/strings/strings.cpp
@@ -172,16 +172,10 @@ void StringTestCase::Format()
         CPPUNIT_ASSERT_EQUAL( len, wxString::Format(wxT("%s"), s.c_str()).length());
     }
 
-    int errnoWas = errno;
     // wxString::Format() should not modify errno
     errno = 1234;
     wxString::Format("abc %d %d", 1, 1);
-    CPPUNIT_ASSERT_EQUAL
-    (
-        1234,
-        errno
-    );
-    errno = errnoWas;
+    CPPUNIT_ASSERT_EQUAL(1234, errno);
 
     // Positional parameters tests:
     CPPUNIT_ASSERT_EQUAL