diff --git a/test/test.h b/test/test.h
index 4e9786c3..085a663d 100644
--- a/test/test.h
+++ b/test/test.h
@@ -97,8 +97,8 @@ extern const char testUTF8Combined[];
 extern const char testUTF8InvalidInput[];
 extern const char testUTF8InvalidOutput[];
 extern bool utf8equal(const char *s, const char *t);
-extern void utf8diffErrorfFull(const char *file, long line, const char *msg, const char *got, const char *want);
-#define utf8diffErrorf(msg, got, want) utf8diffErrorfFull(__FILE__, __LINE__, msg, got, want)
+extern void utf8diffErrorFull(const char *file, long line, const char *msg, const char *got, const char *want);
+#define utf8diffError(msg, got, want) utf8diffErrorFull(__FILE__, __LINE__, msg, got, want)
 
 #ifdef __cplusplus
 }
diff --git a/test/utf8.c b/test/utf8.c
index 62153265..8a073e80 100644
--- a/test/utf8.c
+++ b/test/utf8.c
@@ -83,7 +83,7 @@ static void utf8hexdump(char buf[64], const char *s)
 	}
 }
 
-void utf8diffErrorfFull(const char *file, long line, const char *msg, const char *got, const char *want)
+void utf8diffErrorFull(const char *file, long line, const char *msg, const char *got, const char *want)
 {
 	char a[64], b[64];
 
diff --git a/test/window.c b/test/window.c
index cae1efb2..ece8343e 100644
--- a/test/window.c
+++ b/test/window.c
@@ -26,13 +26,59 @@ Test(InitialWindowTitleIsEmptyString)
 
 	w = uiNewWindow();
 	title = uiWindowTitle(w);
-	// TODO have a utf8cmp()
-	if (*title != 0)
-		// TODO have a diffUTF8
-		TestErrorf("brand new uiWindow has wrong title:" diff("%s"),
-			title, "(empty string)");
+	if (!utf8equal(title, testUTF8Empty))
+		utf8diffError("brand new uiWindow has wrong title", title, testUTF8Empty);
 	uiControlFree(uiControl(w));
 }
 
-// TODO check that SetTitle works, and also that it sanitizes
-// TODO for all the above, check that the underlying title was also set appropriately
+static void testSetWindowTitleImplFull(const char *file, long line, const char *title, const char *want)
+{
+	uiWindow *w;
+	const char *got;
+
+	w = uiNewWindow();
+	uiWindowSetTitle(w, title);
+	got = uiWindowTitle(w);
+	if (!utf8equal(got, want))
+		utf8diffErrorFull(file, line, "uiWindowTitle() reported wrong title after uiWindowSetTitle()", got, want);
+	uiControlFree(uiControl(w));
+}
+
+#define testSetWindowTitleImpl(title, want) testSetWindowTitleImplFull(__FILE__, __LINE__, title, want)
+
+Test(SetWindowTitle_Empty)
+{
+	testSetWindowTitleImpl(testUTF8Empty, testUTF8Empty);
+}
+
+Test(SetWindowTitle_ASCIIOnly)
+{
+	testSetWindowTitleImpl(testUTF8ASCIIOnly, testUTF8ASCIIOnly);
+}
+
+Test(SetWindowTitle_WithTwoByte)
+{
+	testSetWindowTitleImpl(testUTF8WithTwoByte, testUTF8WithTwoByte);
+}
+
+Test(SetWindowTitle_WithThreeByte)
+{
+	testSetWindowTitleImpl(testUTF8WithThreeByte, testUTF8WithThreeByte);
+}
+
+Test(SetWindowTitle_WithFourByte)
+{
+	testSetWindowTitleImpl(testUTF8WithFourByte, testUTF8WithFourByte);
+}
+
+Test(SetWindowTitle_Combined)
+{
+	testSetWindowTitleImpl(testUTF8Combined, testUTF8Combined);
+}
+
+Test(SetWindowTitle_Invalid)
+{
+	testSetWindowTitleImpl(testUTF8InvalidInput, testUTF8InvalidOutput);
+}
+
+// TODO for all the above, check that the underlying OS-level title was also set appropriately