diff --git a/darwin/group.m b/darwin/group.m
index c00b4d29..f8149c48 100644
--- a/darwin/group.m
+++ b/darwin/group.m
@@ -69,8 +69,19 @@ static void uiGroupSyncEnableState(uiDarwinControl *c, int enabled)
 }
 
 uiDarwinControlDefaultSetSuperview(uiGroup, box)
-uiDarwinControlDefaultChildrenShouldAllowSpaceAtTrailingEdge(uiGroup, box)
-uiDarwinControlDefaultChildrenShouldAllowSpaceAtBottom(uiGroup, box)
+
+static BOOL uiGroupChildrenShouldAllowSpaceAtTrailingEdge(uiDarwinControl *c)
+{
+	// always allow growth
+	// TODO actually these should probably only allow growth if the parent does...
+	return YES;
+}
+
+static BOOL uiGroupChildrenShouldAllowSpaceAtBottom(uiDarwinControl *c)
+{
+	// always allow growth
+	return YES;
+}
 
 static void groupRelayout(uiGroup *g)
 {
diff --git a/darwin/tab.m b/darwin/tab.m
index b5ce0283..3138b890 100644
--- a/darwin/tab.m
+++ b/darwin/tab.m
@@ -55,8 +55,18 @@ uiDarwinControlDefaultDisable(uiTab, tabview)
 uiDarwinControlDefaultSyncEnableState(uiTab, tabview)
 
 uiDarwinControlDefaultSetSuperview(uiTab, tabview)
-uiDarwinControlDefaultChildrenShouldAllowSpaceAtTrailingEdge(uiTab, tabview)
-uiDarwinControlDefaultChildrenShouldAllowSpaceAtBottom(uiTab, tabview)
+
+static BOOL uiTabChildrenShouldAllowSpaceAtTrailingEdge(uiDarwinControl *c)
+{
+	// always allow growth
+	return YES;
+}
+
+static BOOL uiTabChildrenShouldAllowSpaceAtBottom(uiDarwinControl *c)
+{
+	// always allow growth
+	return YES;
+}
 
 static void tabRelayout(uiTab *t)
 {
diff --git a/darwin/window.m b/darwin/window.m
index 3f46f5f4..4b2248f4 100644
--- a/darwin/window.m
+++ b/darwin/window.m
@@ -141,8 +141,17 @@ static void uiWindowSetSuperview(uiDarwinControl *c, NSView *superview)
 	// TODO
 }
 
-uiDarwinControlDefaultChildrenShouldAllowSpaceAtTrailingEdge(uiWindow, window)
-uiDarwinControlDefaultChildrenShouldAllowSpaceAtBottom(uiWindow, window)
+static BOOL uiWindowChildrenShouldAllowSpaceAtTrailingEdge(uiDarwinControl *c)
+{
+	// always allow growth
+	return YES;
+}
+
+static BOOL uiWindowChildrenShouldAllowSpaceAtBottom(uiDarwinControl *c)
+{
+	// always allow growth
+	return YES;
+}
 
 static void windowRelayout(uiWindow *w)
 {