diff --git a/ruamoko/include/Array.h b/ruamoko/include/Array.h
index 113e466a9..060f50956 100644
--- a/ruamoko/include/Array.h
+++ b/ruamoko/include/Array.h
@@ -271,7 +271,7 @@
 	Iteratively sends #performSelector:withObject: to each contained object.
 */
 - (void) makeObjectsPerformSelector: (SEL)selector
-                         withObject: (id)arg;
+                         withObject: (void *)arg;
 //\}
 
 @end
diff --git a/ruamoko/include/Object.h b/ruamoko/include/Object.h
index 475e0bec9..eb10e55ef 100644
--- a/ruamoko/include/Object.h
+++ b/ruamoko/include/Object.h
@@ -20,10 +20,10 @@
 
 - (id) performSelector: (SEL)aSelector;
 - (id) performSelector: (SEL)aSelector
-			withObject: (id)anObject;
+			withObject: (void *)anObject;
 - (id) performSelector: (SEL)aSelector
-			withObject: (id)anObject
-			withObject: (id)anotherObject;
+			withObject: (void *)anObject
+			withObject: (void *)anotherObject;
 - (BOOL) respondsToSelector: (SEL)aSelector;
 - (BOOL) conformsToProtocol: (Protocol *)aProtocol;
 
diff --git a/ruamoko/lib/Array.r b/ruamoko/lib/Array.r
index 842076f72..2946141cc 100644
--- a/ruamoko/lib/Array.r
+++ b/ruamoko/lib/Array.r
@@ -162,7 +162,7 @@
 - (id) objectAtIndex: (unsigned)index
 {
 	if (index >= count) // FIXME: need exceptions
-		[self error: "-replaceObjectAtIndex:withObject: index out of range"];
+		[self error: "-objectAtIndex:withObject: index out of range"];
 
 	return _objs[index];
 }
@@ -401,7 +401,7 @@
 }
 
 - (void) makeObjectsPerformSelector: (SEL)selector
-                         withObject: (id)anObject
+                         withObject: (void *)anObject
 {
 	local int	i;
 
diff --git a/ruamoko/lib/Object.r b/ruamoko/lib/Object.r
index dba6b5071..d85a78064 100644
--- a/ruamoko/lib/Object.r
+++ b/ruamoko/lib/Object.r
@@ -247,7 +247,7 @@ BOOL (id object) object_is_meta_class = #0;
 	return msg (self, aSelector);
 }
 
-- (id) performSelector: (SEL)aSelector withObject: (id)anObject
+- (id) performSelector: (SEL)aSelector withObject: (void *)anObject
 {
 	local IMP msg = nil;		// FIXME teach qfcc about noreturn
 
@@ -260,8 +260,8 @@ BOOL (id object) object_is_meta_class = #0;
 }
 
 - (id) performSelector: (SEL)aSelector
-			withObject: (id)anObject
-			withObject: (id)anotherObject
+			withObject: (void *)anObject
+			withObject: (void *)anotherObject
 {
 	local IMP msg;