diff --git a/TODO.md b/TODO.md
index efd24b1b..790ee5d8 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,3 +1,4 @@
+- refine logging
 - figure out how to deal with dchild at all, including preferred sizes
 - make OS X uiEntry width based on default in Interface Builder, not from sizeToFit
 - update state whenever setting parent
diff --git a/redo/test/main.c b/redo/test/main.c
index dbb6291c..c651c267 100644
--- a/redo/test/main.c
+++ b/redo/test/main.c
@@ -15,14 +15,14 @@ void die(const char *fmt, ...)
 
 int onClosing(uiWindow *w, void *data)
 {
-	printf("in onClosing()\n");
+	uiLog("[test program] in onClosing()\n");
 	uiQuit();
 	return 1;
 }
 
 int onShouldQuit(void *data)
 {
-	printf("in onShouldQuit()\n");
+	uiLog("[test program] in onShouldQuit()\n");
 	if (uiMenuItemChecked(shouldQuitItem)) {
 		uiControlDestroy(uiControl(data));
 		return 1;
@@ -72,7 +72,7 @@ int main(int argc, char *argv[])
 
 	w = newWindow("Main Window", 320, 240, 1);
 	uiWindowOnClosing(w, onClosing, NULL);
-	printf("main window %p\n", w);
+	uiLog("[test program] main window %p\n", w);
 
 	uiOnShouldQuit(onShouldQuit, w);
 
@@ -103,8 +103,8 @@ int main(int argc, char *argv[])
 
 	uiControlShow(uiControl(w));
 	uiMain();
-	printf("after uiMain()\n");
+	uiLog("[test program] after uiMain()\n");
 	uiUninit();
-	printf("after uiUninit()\n");
+	uiLog("[test program] after uiUninit()\n");
 	return 0;
 }
diff --git a/redo/test/page1.c b/redo/test/page1.c
index 2115ba26..29aaf945 100644
--- a/redo/test/page1.c
+++ b/redo/test/page1.c
@@ -27,7 +27,7 @@ TEXT(Group, uiGroup, uiGroupTitle, uiGroupSetTitle)
 
 static void onChanged(uiEntry *e, void *data)
 {
-	printf("onChanged()\n");
+	uiLog("[test program] onChanged()\n");
 }
 
 static void toggleSpaced(uiCheckbox *c, void *data)
diff --git a/redo/test/page4.c b/redo/test/page4.c
index a68153c0..341d1493 100644
--- a/redo/test/page4.c
+++ b/redo/test/page4.c
@@ -9,7 +9,7 @@ static uiProgressBar *pbar;
 	static void on ## what ## Changed(ui ## what *this, void *data) \
 	{ \
 		uintmax_t value; \
-		printf("on %s changed\n", #what); \
+		uiLog("[test program] on %s changed\n", #what); \
 		value = ui ## what ## Value(this); \
 		uiSpinboxSetValue(spinbox, value); \
 		uiSliderSetValue(slider, value); \
diff --git a/redo/ui.idl b/redo/ui.idl
index dd83fa3e..afc34f12 100644
--- a/redo/ui.idl
+++ b/redo/ui.idl
@@ -28,6 +28,9 @@ func OnShouldQuit(f *func(data *void) int, data *void);
 
 func FreeText(text *char);
 
+// TODO add ... to IDL
+raw "_UI_EXTERN void uiLog(const char *format, ...);";
+
 func RegisterType(name *const char, parent uintmax_t, size size_t) uintmax_t;
 func IsA(p *void, type uintmax_t, fail int) *void;
 struct Typed {
diff --git a/redo/windows/util.c b/redo/windows/util.c
index eb5a0e30..8011a1ae 100644
--- a/redo/windows/util.c
+++ b/redo/windows/util.c
@@ -34,6 +34,21 @@ int windowClassOf(HWND hwnd, ...)
 	return -1;
 }
 
+// TODO refine this
+void uiLog(const char *fmt, ...)
+{
+	va_list ap;
+	char buf[2048];
+
+	va_start(ap, fmt);
+	vsnprintf(buf, 2044, fmt, ap);
+	va_end(ap);
+	// unfortunately we need to make sure this is callable even before uiInit() executes or after uiUninit() has executed
+	// that means we can't use toUTF16(), because that requires our private heap
+	// sadly that means we're stuck with OutputDebugStringA() without some serious refinement
+	OutputDebugStringA(buf);
+}
+
 void complain(const char *fmt, ...)
 {
 	va_list ap;