diff --git a/tests/exec/exec.cpp b/tests/exec/exec.cpp
index e3be763544..bc2cdfe052 100644
--- a/tests/exec/exec.cpp
+++ b/tests/exec/exec.cpp
@@ -171,6 +171,11 @@ void ExecTestCase::TestShell()
 
 void ExecTestCase::TestExecute()
 {
+    // Launching interactive programs doesn't work without an interactive
+    // session.
+    if ( IsAutomaticTest() )
+        return;
+
     AsyncInEventLoop asyncInEventLoop;
 
     // test asynch exec
@@ -238,6 +243,9 @@ void ExecTestCase::TestExecute()
 
 void ExecTestCase::TestProcess()
 {
+    if ( IsAutomaticTest() )
+        return;
+
     AsyncInEventLoop asyncInEventLoop;
 
     // test wxExecute with wxProcess
diff --git a/tests/filekind/filekind.cpp b/tests/filekind/filekind.cpp
index aa812b0884..fa270897b4 100644
--- a/tests/filekind/filekind.cpp
+++ b/tests/filekind/filekind.cpp
@@ -37,6 +37,8 @@
     #define fileno _fileno
 #endif
 
+#include "testfile.h"
+
 ///////////////////////////////////////////////////////////////////////////////
 // The test case
 
@@ -100,23 +102,17 @@ void FileKindTestCase::TestFd(wxFile& file, bool expected)
     CPPUNIT_ASSERT(outStream.IsSeekable() == expected);
 }
 
-struct TempFile
-{
-    ~TempFile() { if (!m_name.IsEmpty()) wxRemoveFile(m_name); }
-    wxString m_name;
-};
-
 // test with an ordinary file
 //
 void FileKindTestCase::File()
 {
     TempFile tmp; // put first
     wxFile file;
-    tmp.m_name = wxFileName::CreateTempFileName(wxT("wxft"), &file);
+    tmp.Assign(wxFileName::CreateTempFileName(wxT("wxft"), &file));
     TestFd(file, true);
     file.Close();
 
-    wxFFile ffile(tmp.m_name);
+    wxFFile ffile(tmp.GetName());
     TestFILE(ffile, true);
 }
 
diff --git a/tests/mbconv/mbconvtest.cpp b/tests/mbconv/mbconvtest.cpp
index 0b2b1507c6..5a0afa4e5b 100644
--- a/tests/mbconv/mbconvtest.cpp
+++ b/tests/mbconv/mbconvtest.cpp
@@ -1484,8 +1484,8 @@ TEST_CASE("wxMBConv::cMB2WC", "[mbconv][mb2wc]")
 
     CHECK( convUTF16.cMB2WC("\0").length() == 0 );
     CHECK( convUTF16.cMB2WC(wxCharBuffer()).length() == 0 );
-    CHECK( convUTF16.cMB2WC("H\0i\0").length() == 2 );
-    CHECK( convUTF16.cMB2WC(wxCharBuffer::CreateNonOwned("H\0i\0", 4)).length() == 2 );
+    CHECK( convUTF16.cMB2WC("H\0i\0\0").length() == 2 );
+    CHECK( convUTF16.cMB2WC(wxCharBuffer::CreateNonOwned("H\0i\0\0", 4)).length() == 2 );
 
     CHECK( wxConvUTF7.cMB2WC("").length() == 0 );
     CHECK( wxConvUTF7.cMB2WC(wxCharBuffer()).length() == 0 );
diff --git a/tests/streams/datastreamtest.cpp b/tests/streams/datastreamtest.cpp
index ae6c1564ad..ca2456a6c5 100644
--- a/tests/streams/datastreamtest.cpp
+++ b/tests/streams/datastreamtest.cpp
@@ -26,6 +26,8 @@
 #include "wx/wfstream.h"
 #include "wx/math.h"
 
+#include "testfile.h"
+
 // ----------------------------------------------------------------------------
 // test class
 // ----------------------------------------------------------------------------
@@ -107,8 +109,10 @@ DataStreamTestCase::DataStreamTestCase()
 
 wxFloat64 DataStreamTestCase::TestFloatRW(wxFloat64 fValue)
 {
+    TempFile f("mytext.dat");
+
     {
-        wxFileOutputStream pFileOutput( wxT("mytext.dat") );
+        wxFileOutputStream pFileOutput( f.GetName() );
         wxDataOutputStream pDataOutput( pFileOutput );
         if ( ms_useBigEndianFormat )
             pDataOutput.BigEndianOrdered(true);
@@ -121,7 +125,7 @@ wxFloat64 DataStreamTestCase::TestFloatRW(wxFloat64 fValue)
         pDataOutput << fValue;
     }
 
-    wxFileInputStream pFileInput( wxT("mytext.dat") );
+    wxFileInputStream pFileInput( f.GetName() );
     wxDataInputStream pDataInput( pFileInput );
     if ( ms_useBigEndianFormat )
         pDataInput.BigEndianOrdered(true);
@@ -156,15 +160,17 @@ private:
     {
         ValueArray InValues(Size);
 
+        TempFile f("mytext.dat");
+
         {
-            wxFileOutputStream FileOutput( wxT("mytext.dat") );
+            wxFileOutputStream FileOutput( f.GetName() );
             wxDataOutputStream DataOutput( FileOutput );
 
             (DataOutput.*pfnWriter)(Values, Size);
         }
 
         {
-            wxFileInputStream FileInput( wxT("mytext.dat") );
+            wxFileInputStream FileInput( f.GetName() );
             wxDataInputStream DataInput( FileInput );
 
             (DataInput.*pfnReader)(&*InValues.begin(), InValues.size());
@@ -207,15 +213,17 @@ T TestRW(const T &Value)
 {
     T InValue;
 
+    TempFile f("mytext.dat");
+
     {
-        wxFileOutputStream FileOutput( wxT("mytext.dat") );
+        wxFileOutputStream FileOutput( f.GetName() );
         wxDataOutputStream DataOutput( FileOutput );
 
         DataOutput << Value;
     }
 
     {
-        wxFileInputStream FileInput( wxT("mytext.dat") );
+        wxFileInputStream FileInput( f.GetName() );
         wxDataInputStream DataInput( FileInput );
 
         DataInput >> InValue;
diff --git a/tests/streams/textstreamtest.cpp b/tests/streams/textstreamtest.cpp
index ec88c01ec8..0975e7526e 100644
--- a/tests/streams/textstreamtest.cpp
+++ b/tests/streams/textstreamtest.cpp
@@ -31,6 +31,8 @@
     #include "wx/mstream.h"
 #endif // wxUSE_UNICODE
 
+#include "testfile.h"
+
 // ----------------------------------------------------------------------------
 // test class
 // ----------------------------------------------------------------------------
@@ -105,23 +107,22 @@ TextStreamTestCase::TextStreamTestCase()
 
 void TextStreamTestCase::Endline()
 {
-    wxFileOutputStream* pOutFile = new wxFileOutputStream(wxT("test.txt"));
-    wxTextOutputStream* pOutText = new wxTextOutputStream(*pOutFile);
-    *pOutText   << wxT("Test text") << endl
-                << wxT("More Testing Text (There should be newline before this)");
+    TempFile f("test.txt");
 
-    delete pOutText;
-    delete pOutFile;
+    {
+        wxFileOutputStream pOutFile(f.GetName());
+        wxTextOutputStream pOutText(pOutFile);
+        pOutText << wxT("Test text") << endl
+                 << wxT("More Testing Text (There should be newline before this)");
+    }
 
-    wxFileInputStream* pInFile = new wxFileInputStream(wxT("test.txt"));
+    wxFileInputStream pInFile(f.GetName());
 
     char szIn[9 + NEWLINELEN];
 
-    pInFile->Read(szIn, 9 + NEWLINELEN);
+    pInFile.Read(szIn, 9 + NEWLINELEN);
 
     CPPUNIT_ASSERT( memcmp(&szIn[9], NEWLINE, NEWLINELEN) == 0 );
-
-    delete pInFile;
 }
 
 void TextStreamTestCase::MiscTests()
@@ -147,8 +148,10 @@ void TextStreamTestCase::MiscTests()
 template <typename T>
 static void DoTestRoundTrip(const T *values, size_t numValues)
 {
+    TempFile f("test.txt");
+
     {
-        wxFileOutputStream fileOut(wxT("test.txt"));
+        wxFileOutputStream fileOut(f.GetName());
         wxTextOutputStream textOut(fileOut);
 
         for ( size_t n = 0; n < numValues; n++ )
@@ -158,7 +161,7 @@ static void DoTestRoundTrip(const T *values, size_t numValues)
     }
 
     {
-        wxFileInputStream fileIn(wxT("test.txt"));
+        wxFileInputStream fileIn(f.GetName());
         wxTextInputStream textIn(fileIn);
 
         T value;
diff --git a/tests/test.cpp b/tests/test.cpp
index 5e2f6c5c7d..ba853d53ea 100644
--- a/tests/test.cpp
+++ b/tests/test.cpp
@@ -360,6 +360,37 @@ extern bool IsAutomaticTest()
 
 #if wxUSE_GUI
 
+bool EnableUITests()
+{
+    static int s_enabled = -1;
+    if ( s_enabled == -1 )
+    {
+        // Allow explicitly configuring this via an environment variable under
+        // all platforms.
+        wxString enabled;
+        if ( wxGetEnv("WX_UI_TESTS", &enabled) )
+        {
+            if ( enabled == "1" )
+                s_enabled = 1;
+            else if ( enabled == "0" )
+                s_enabled = 0;
+            else
+                wxFprintf(stderr, "Unknown \"WX_UI_TESTS\" value \"%s\" ignored.\n", enabled);
+        }
+
+        if ( s_enabled == -1 )
+        {
+#ifdef __WXMSW__
+            s_enabled = 1;
+#else // !__WXMSW__
+            s_enabled = 0;
+#endif // __WXMSW__/!__WXMSW__
+        }
+    }
+
+    return s_enabled == 1;
+}
+
 void DeleteTestWindow(wxWindow* win)
 {
     if ( !win )
diff --git a/tests/testfile.h b/tests/testfile.h
index 519acbe8b2..9c1f5afa3d 100644
--- a/tests/testfile.h
+++ b/tests/testfile.h
@@ -41,5 +41,30 @@ private:
     wxString m_name;
 };
 
+// ----------------------------------------------------------------------------
+// TempFile: just a self deleting file
+// ----------------------------------------------------------------------------
+
+class TempFile
+{
+public:
+    explicit TempFile(const wxString& name = wxString()) : m_name(name) { }
+
+    void Assign(const wxString& name) { m_name = name; }
+
+    const wxString& GetName() const { return m_name; }
+
+    ~TempFile()
+    {
+        if ( !m_name.empty() )
+            wxRemoveFile(m_name);
+    }
+
+private:
+    wxString m_name;
+
+    wxDECLARE_NO_COPY_CLASS(TempFile);
+};
+
 #endif // _WX_TESTS_TEMPFILE_H_
 
diff --git a/tests/testprec.h b/tests/testprec.h
index 8bbaf4be70..f5661446ed 100644
--- a/tests/testprec.h
+++ b/tests/testprec.h
@@ -10,13 +10,14 @@
 // this allows the tests that do not rely on it to run on platforms that don't
 // support it.
 //
-// FIXME: And while OS X does support it, more or less, too many tests
-//        currently fail under it so disable all interactive tests there. They
-//        should, of course, be reenabled a.s.a.p.
-#if wxUSE_UIACTIONSIMULATOR && !defined(__WXOSX__)
-    #define WXUISIM_TEST(test) CPPUNIT_TEST(test)
+// Unfortunately, currently too many of the UI tests fail on non-MSW platforms,
+// so they're disabled there by default. This really, really needs to be fixed,
+// but for now having the UI tests always failing is not helpful as it prevents
+// other test failures from being noticed, so disable them there.
+#if wxUSE_UIACTIONSIMULATOR
+    #define WXUISIM_TEST(test) if ( EnableUITests() ) { CPPUNIT_TEST(test) }
 #else
-    #define WXUISIM_TEST(test) (void)0
+    #define WXUISIM_TEST(test)
 #endif
 
 // define wxHAVE_U_ESCAPE if the compiler supports \uxxxx character constants
@@ -169,6 +170,9 @@ private:
 
 #if wxUSE_GUI
 
+// Return true if the UI tests are enabled, used by WXUISIM_TEST().
+extern bool EnableUITests();
+
 // Helper function deleting the window without asserts (and hence exceptions
 // thrown from its dtor!) even if it has mouse capture.
 void DeleteTestWindow(wxWindow* win);