Index: source/ps/tests/test_CStr.h
===================================================================
--- source/ps/tests/test_CStr.h
+++ source/ps/tests/test_CStr.h
@@ -132,7 +132,7 @@
 		TS_ASSERT_EQUALS(str2.ToLong(), 0);
 		TS_ASSERT_EQUALS(str2.ToULong(), 0u);
 
-		CStr8 str3("3bogus");
+		CStr8 str3("3 bogus");
 		TS_ASSERT_EQUALS(str3.ToFloat(), 3.0f);
 		TS_ASSERT_EQUALS(str3.ToDouble(), 3.0);
 		TS_ASSERT_EQUALS(str3.ToInt(), 3);
Index: source/ps/tests/test_cppformat.h
===================================================================
--- source/ps/tests/test_cppformat.h
+++ source/ps/tests/test_cppformat.h
@@ -24,6 +24,10 @@
 public:
 	void test_basic()
 	{
+		// Make test behave independent of current host locale
+		char* old = setlocale(LC_ALL, NULL);
+		setlocale(LC_ALL, "en_US.UTF-8");
+
 		TS_ASSERT_EQUALS(fmt::sprintf("abc"), "abc");
 
 		TS_ASSERT_EQUALS(fmt::sprintf("%d", 123), "123");
@@ -54,5 +58,7 @@
 		TS_ASSERT_EQUALS(fmt::sprintf("T%sT", (const char*)NULL), "T(null)T");
 
 		TS_ASSERT_EQUALS(fmt::sprintf("T%pT", (void*)0x1234), "T0x1234T");
+
+		setlocale(LC_ALL, old);
 	}
 };