diff --git a/tests/file/filefn.cpp b/tests/file/filefn.cpp
index 4207545835..c347639d75 100644
--- a/tests/file/filefn.cpp
+++ b/tests/file/filefn.cpp
@@ -86,7 +86,9 @@ private:
                       const wxString& destFilePath);
 
     wxString m_fileNameASCII;
+#if wxUSE_UNICODE
     wxString m_fileNameNonASCII;
+#endif // wxUSE_UNICODE
     wxString m_fileNameWork;
 
     wxDECLARE_NO_COPY_CLASS(FileFunctionsTestCase);
@@ -110,10 +112,12 @@ void FileFunctionsTestCase::setUp()
     wxFileName fn1(wxFileName::GetTempDir(), wxT("wx_file_mask.txt"));
     m_fileNameASCII = fn1.GetFullPath();
 
+#if wxUSE_UNICODE
     // This file name is 'wx_file_mask.txt' in Russian.
     wxFileName fn2(wxFileName::GetTempDir(),
       wxT("wx_\u043C\u0430\u0441\u043A\u0430_\u0444\u0430\u0439\u043B\u0430.txt"));
     m_fileNameNonASCII = fn2.GetFullPath();
+#endif // wxUSE_UNICODE
 
     wxFileName fn3(wxFileName::GetTempDir(), wxT("wx_test_copy"));
     m_fileNameWork = fn3.GetFullPath();
@@ -126,10 +130,12 @@ void FileFunctionsTestCase::tearDown()
     {
         wxRemoveFile(m_fileNameASCII);
     }
+#if wxUSE_UNICODE
     if ( wxFileExists(m_fileNameNonASCII) )
     {
         wxRemoveFile(m_fileNameNonASCII);
     }
+#endif // wxUSE_UNICODE
     if ( wxFileExists(m_fileNameWork) )
     {
         wxRemoveFile(m_fileNameWork);
@@ -176,8 +182,10 @@ void FileFunctionsTestCase::CreateFile()
 {
     // Create file name containing ASCII characters only.
     DoCreateFile(m_fileNameASCII);
+#if wxUSE_UNICODE
     // Create file name containing non-ASCII characters.
     DoCreateFile(m_fileNameNonASCII);
+#endif // wxUSE_UNICODE
 }
 
 void FileFunctionsTestCase::DoCreateFile(const wxString& filePath)
@@ -199,8 +207,10 @@ void FileFunctionsTestCase::FileExists()
 
     // Check file name containing ASCII characters only.
     DoFileExists(m_fileNameASCII);
+#if wxUSE_UNICODE
     // Check file name containing non-ASCII characters.
     DoFileExists(m_fileNameNonASCII);
+#endif // wxUSE_UNICODE
 }
 
 void FileFunctionsTestCase::DoFileExists(const wxString& filePath)
@@ -223,8 +233,10 @@ void FileFunctionsTestCase::FindFile()
 {
     // Find file name containing ASCII characters only.
     DoFindFile(m_fileNameASCII);
+#if wxUSE_UNICODE
     // Find file name containing non-ASCII characters.
     DoFindFile(m_fileNameNonASCII);
+#endif // wxUSE_UNICODE
 }
 
 void FileFunctionsTestCase::DoFindFile(const wxString& filePath)
@@ -283,8 +295,10 @@ void FileFunctionsTestCase::RemoveFile()
 {
     // Create & remove file with name containing ASCII characters only.
     DoRemoveFile(m_fileNameASCII);
+#if wxUSE_UNICODE
     // Create & remove file with name containing non-ASCII characters.
     DoRemoveFile(m_fileNameNonASCII);
+#endif // wxUSE_UNICODE
 }
 
 void FileFunctionsTestCase::DoRemoveFile(const wxString& filePath)
@@ -305,6 +319,7 @@ void FileFunctionsTestCase::RenameFile()
 {
     // Verify renaming file with/without overwriting
     // when new file already exist/don't exist.
+#if wxUSE_UNICODE
     DoRenameFile(m_fileNameASCII, m_fileNameNonASCII, false, false);
     DoRenameFile(m_fileNameASCII, m_fileNameNonASCII, false, true);
     DoRenameFile(m_fileNameASCII, m_fileNameNonASCII, true, false);
@@ -313,6 +328,7 @@ void FileFunctionsTestCase::RenameFile()
     DoRenameFile(m_fileNameNonASCII, m_fileNameASCII, false, true);
     DoRenameFile(m_fileNameNonASCII, m_fileNameASCII, true, false);
     DoRenameFile(m_fileNameNonASCII, m_fileNameASCII, true, true);
+#endif // wxUSE_UNICODE
 }
 
 void
@@ -378,8 +394,10 @@ FileFunctionsTestCase::DoRenameFile(const wxString& oldFilePath,
 
 void FileFunctionsTestCase::ConcatenateFiles()
 {
+#if wxUSE_UNICODE
     DoConcatFile(m_fileNameASCII, m_fileNameNonASCII, m_fileNameWork);
     DoConcatFile(m_fileNameNonASCII, m_fileNameASCII, m_fileNameWork);
+#endif // wxUSE_UNICODE
 }
 
 void FileFunctionsTestCase::DoConcatFile(const wxString& filePath1,
@@ -525,21 +543,25 @@ void FileFunctionsTestCase::PathOnly()
 // Rmdir fails on them on Linux. See ticket #17644.
 void FileFunctionsTestCase::Mkdir()
 {
+#if wxUSE_UNICODE
     wxString dirname = wxString::FromUTF8("__wxMkdir_test_dir_with_\xc3\xb6");
     const std::string msg = wxString::Format("Dir: %s", dirname).ToStdString();
     CPPUNIT_ASSERT_MESSAGE( msg, wxMkdir(dirname) );
     CPPUNIT_ASSERT_MESSAGE( msg, wxDirExists(dirname) );
     CPPUNIT_ASSERT_MESSAGE( msg, wxRmdir(dirname) );
+#endif // wxUSE_UNICODE
 }
 
 void FileFunctionsTestCase::Rmdir()
 {
+#if wxUSE_UNICODE
     wxString dirname = wxString::FromUTF8("__wxRmdir_test_dir_with_\xc3\xb6");
     const std::string msg = wxString::Format("Dir: %s", dirname).ToStdString();
 
     CPPUNIT_ASSERT_MESSAGE( msg, wxMkdir(dirname) );
     CPPUNIT_ASSERT_MESSAGE( msg, wxRmdir(dirname) );
     CPPUNIT_ASSERT_MESSAGE( msg, !wxDirExists(dirname) );
+#endif // wxUSE_UNICODE
 }
 
 /*
diff --git a/tests/streams/datastreamtest.cpp b/tests/streams/datastreamtest.cpp
index a98c3af3ed..27bf25aa92 100644
--- a/tests/streams/datastreamtest.cpp
+++ b/tests/streams/datastreamtest.cpp
@@ -248,9 +248,11 @@ void DataStreamTestCase::StringRW()
     wxString s(wxT("Test1"));
     CPPUNIT_ASSERT_EQUAL( TestRW(s), s );
 
+#if wxUSE_UNICODE
     s.append(2, wxT('\0'));
     s.append(wxT("Test2"));
     CPPUNIT_ASSERT_EQUAL( TestRW(s), s );
+#endif // wxUSE_UNICODE
 
     s = wxString::FromUTF8("\xc3\xbc"); // U+00FC LATIN SMALL LETTER U WITH DIAERESIS
     CPPUNIT_ASSERT_EQUAL( TestRW(s), s );
diff --git a/tests/streams/sstream.cpp b/tests/streams/sstream.cpp
index 1bff584180..a17640c3e8 100644
--- a/tests/streams/sstream.cpp
+++ b/tests/streams/sstream.cpp
@@ -131,7 +131,7 @@ TEST_CASE("wxStringOutputStream::Tell", "[stream]")
     wxString str(s);
     CHECK( wxStringOutputStream(&str).TellO() == len );
 
-
+#if wxUSE_UNICODE
     wxMBConvUTF16 convUTF16;
     wxStringOutputStream ss16(NULL, convUTF16);
     CHECK( ss16.TellO() == 0 );
@@ -144,4 +144,5 @@ TEST_CASE("wxStringOutputStream::Tell", "[stream]")
     // The U+2070D character is represented by a surrogate pair in UTF-16.
     wxString u2070D = wxString::FromUTF8("\xF0\xA0\x9C\x8D");
     CHECK( wxStringOutputStream(&u2070D, convUTF16).TellO() == 4 );
+#endif // wxUSE_UNICODE
 }
diff --git a/tests/strings/stdstrings.cpp b/tests/strings/stdstrings.cpp
index 550684f5da..1f9a6b3d66 100644
--- a/tests/strings/stdstrings.cpp
+++ b/tests/strings/stdstrings.cpp
@@ -636,9 +636,11 @@ void StdStringTestCase::StdConversion()
     wxStdWideString s8(s4);
     CPPUNIT_ASSERT( s8 == "hello" );
 
+#if wxUSE_UNICODE
     std::string s9("\xF0\x9F\x90\xB1\0\xE7\x8C\xAB", 9); /* U+1F431 U+0000 U+732B */
     wxString s10 = wxString::FromUTF8(s9);
     CPPUNIT_ASSERT_EQUAL( s9, s10.ToStdString(wxConvUTF8) );
+#endif // wxUSE_UNICODE
 
     std::string s11("xyz\0\xFF", 5); /* an invalid UTF-8 sequence */
     CPPUNIT_ASSERT_EQUAL( wxString::FromUTF8(s11), "" );
diff --git a/tests/strings/strings.cpp b/tests/strings/strings.cpp
index be7215905c..8bbe9d69ad 100644
--- a/tests/strings/strings.cpp
+++ b/tests/strings/strings.cpp
@@ -260,7 +260,9 @@ void StringTestCase::StaticConstructors()
     CPPUNIT_ASSERT_EQUAL( "Hello", wxString::FromUTF8("Hello", 5) );
     CPPUNIT_ASSERT_EQUAL( "Hello", wxString::FromUTF8("Hello") );
 
+#if wxUSE_UNICODE
     CPPUNIT_ASSERT_EQUAL( 2, wxString::FromUTF8("h\xc3\xa9llo", 3).length() );
+#endif // wxUSE_UNICODE
 
 
     //CPPUNIT_ASSERT_EQUAL( 1, wxString::FromUTF8("", 1).length() );