diff --git a/redo/objc_darwin.h b/redo/objc_darwin.h
index 4066b5a..14164f0 100644
--- a/redo/objc_darwin.h
+++ b/redo/objc_darwin.h
@@ -38,7 +38,7 @@ struct xpoint {
 
 /* uitask_darwin.m */
 extern id getAppDelegate(void);	/* used by the other .m files */
-extern BOOL uiinit(void);
+extern void uiinit(char **);
 extern void uimsgloop(void);
 extern void uistop(void);
 extern void issue(void *);
diff --git a/redo/uitask_darwin.go b/redo/uitask_darwin.go
index 9218c8e..094ba01 100644
--- a/redo/uitask_darwin.go
+++ b/redo/uitask_darwin.go
@@ -3,6 +3,7 @@
 package ui
 
 import (
+	"fmt"
 	"unsafe"
 )
 
@@ -12,8 +13,13 @@ import (
 import "C"
 
 func uiinit() error {
-	// TODO check error
-	C.uiinit()
+	var errmsg *C.char
+
+	errmsg = nil
+	C.uiinit(&errmsg)
+	if errmsg != nil {
+		return fmt.Errorf("package ui initialization failed: %s", C.GoString(errmsg))
+	}
 	return nil
 }
 
diff --git a/redo/uitask_darwin.m b/redo/uitask_darwin.m
index 7dc4881..0f4d774 100644
--- a/redo/uitask_darwin.m
+++ b/redo/uitask_darwin.m
@@ -56,7 +56,7 @@ id getAppDelegate(void)
 	return appDelegate;
 }
 
-BOOL uiinit(void)
+void uiinit(char **errmsg)
 {
 	areaClass = getAreaClass();
 	appDelegate = [appDelegateClass new];
@@ -66,7 +66,6 @@ BOOL uiinit(void)
 	[NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
 	[NSApp activateIgnoringOtherApps:YES];		// TODO rsc does this; finder says NO?
 	[NSApp setDelegate:appDelegate];
-	return YES;
 }
 
 void uimsgloop(void)