diff --git a/dlib/test/string.cpp b/dlib/test/string.cpp
index 18f9035c5f..09ac3e304b 100644
--- a/dlib/test/string.cpp
+++ b/dlib/test/string.cpp
@@ -145,9 +145,9 @@ namespace
 
         wstring ws = L"file.txt";
         DLIB_TEST( (left_substr(ws,wstring(L".")) == L"file"));
-        DLIB_TEST_MSG( (left_substr(ws,L".") == L"file"), L"");
+        DLIB_TEST_MSG( (left_substr(ws,L".") == L"file"), "");
         DLIB_TEST( (right_substr(ws,wstring(L".")) == L"txt"));
-        DLIB_TEST_MSG( (right_substr(ws,L".") == L"txt"), L"");
+        DLIB_TEST_MSG( (right_substr(ws,L".") == L"txt"), "");
 
 
         dlog << LTRACE << 8;
diff --git a/dlib/test/tokenizer.cpp b/dlib/test/tokenizer.cpp
index f4300666a2..24d24906ea 100644
--- a/dlib/test/tokenizer.cpp
+++ b/dlib/test/tokenizer.cpp
@@ -394,10 +394,10 @@ namespace
         deserialize(loaded_test, in_stream);
 
         std::vector<std::string> test_strings = {
-            u8"This is a test of the tokenisation process...\nimplemented in the Dlib library!", // English
-            u8"Ceci est un test du processus de\ntokenisation implémenté dans\nla bibliothèque Dlib!", // French
-            u8"Dette er en test af tokeniseringsprocessen implementeret i Dlib-biblioteket!", // Danish
-            u8"这是对Dlib库中实现的标记化过程的测试！" // Chinese
+            "This is a test of the tokenisation process...\nimplemented in the Dlib library!", // English
+            "Ceci est un test du processus de\ntokenisation implémenté dans\nla bibliothèque Dlib!", // French
+            "Dette er en test af tokeniseringsprocessen implementeret i Dlib-biblioteket!", // Danish
+            "这是对Dlib库中实现的标记化过程的测试！" // Chinese
         };
 
         for (const auto& text : test_strings) {