diff --git a/common/programmererrors.h b/common/programmererrors.h
index 26f9597b..4c341706 100644
--- a/common/programmererrors.h
+++ b/common/programmererrors.h
@@ -79,3 +79,11 @@
 	uiprivProgrammerError("%s(): cannot create a parent cycle", func)
 
 // }
+
+// windows {
+
+// TODO have any parameters, such as what the window is and what the parent is? to add func we'll need to carry that out from uiControlSetParent() (which means exposing that in the API)
+#define uiprivProgrammerErrorCannotHaveWindowsAsChildren() \
+	uiprivProgrammerError("cannot set a uiWindow as the child of another uiControl")
+
+// }
diff --git a/darwin/meson.build b/darwin/meson.build
index a4a18d42..a1454f07 100644
--- a/darwin/meson.build
+++ b/darwin/meson.build
@@ -3,6 +3,7 @@
 libui_sources += [
 	'darwin/controls.m',
 	'darwin/main.m',
+	'darwin/window.m',
 ]
 
 libui_deps += [
diff --git a/darwin/window.m b/darwin/window.m
index fe9d49e9..a050a35c 100644
--- a/darwin/window.m
+++ b/darwin/window.m
@@ -249,16 +249,6 @@ static void uiWindowChildVisibilityChanged(uiDarwinControl *c)
 	windowRelayout(w);
 }
 
-char *uiWindowTitle(uiWindow *w)
-{
-	return uiDarwinNSStringToText([w->window title]);
-}
-
-void uiWindowSetTitle(uiWindow *w, const char *title)
-{
-	[w->window setTitle:uiprivToNSString(title)];
-}
-
 void uiWindowContentSize(uiWindow *w, int *width, int *height)
 {
 	NSRect r;
@@ -375,19 +365,20 @@ static void defaultOnPositionContentSizeChanged(uiWindow *w, void *data)
 
 static bool windowInit(uiControl *c, void *implData, void *initData)
 {
-	windowImplData *w = (windowImplData *) implData;
+	struct windowImplData *wi = (struct windowImplData *) implData;
 
-	w->window = [[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, TODO, TODO)
+	// TODO grab the exact values from Interface Builder
+	wi->window = [[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, 100, 100)
 		styleMask:defaultStyleMask
 		backing:NSBackingStoreBuffered
 		defer:YES];
 
-	w->title = NULL;
-	[w->window setTitle:@""];
+	wi->title = NULL;
+	[wi->window setTitle:@""];
 
 	// do NOT release when closed
 	// we manually do this in uiWindowDestroy() above
-	[w->window setReleasedWhenClosed:NO];
+	[wi->window setReleasedWhenClosed:NO];
 
 #if 0
 	if (windowDelegate == nil) {
@@ -404,14 +395,24 @@ static bool windowInit(uiControl *c, void *implData, void *initData)
 
 static void windowFree(uiControl *c, void *implData)
 {
+	struct windowImplData *wi = (struct windowImplData *) implData;
+
+	if (wi->title != NULL) {
+		uiprivFreeUTF8(wi->title);
+		wi->title = NULL;
+	}
+	[wi->window release];
+	wi->window = nil;
 }
 
 static void windowParentChanging(uiControl *c, void *implData, uiControl *oldParent)
 {
+	uiprivProgrammerErrorCannotHaveWindowsAsChildren();
 }
 
 static void windowParentChanged(uiControl *c, void *implData, uiControl *newParent)
 {
+	uiprivProgrammerErrorCannotHaveWindowsAsChildren();
 }
 
 static const uiControlVtable windowVtable = {
@@ -431,7 +432,7 @@ static uint32_t windowType = 0;
 uint32_t uiWindowType(void)
 {
 	if (windowType == 0)
-		windowType = uiRegisterControlType("uiWindow", &windowVtable, &windowOSVtable, sizeof (windowImplData));
+		windowType = uiRegisterControlType("uiWindow", &windowVtable, &windowOSVtable, sizeof (struct windowImplData));
 	return windowType;
 }
 
@@ -442,14 +443,21 @@ uiWindow *uiNewWindow(void)
 
 const char *uiWindowTitle(uiWindow *w)
 {
-	if (w->title == NULL)
+	struct windowImplData *wi = (struct windowImplData *) uiControlImplData(uiControl(w));
+
+	if (wi->title == NULL)
 		return "";
-	return w->title;
+	return wi->title;
 }
 
 void uiWindowSetTitle(uiWindow *w, const char *title)
 {
-	// TODO
+	struct windowImplData *wi = (struct windowImplData *) uiControlImplData(uiControl(w));
+
+	if (wi->title != NULL)
+		uiprivFreeUTF8(wi->title);
+	wi->title = uiprivSanitizeUTF8(title);
+	[wi->window setTitle:[NSString stringWithUTF8String:wi->title]];
 }
 
 #if 0