diff --git a/util.d b/util.d
index 3646dee..6cc4411 100644
--- a/util.d
+++ b/util.d
@@ -198,31 +198,31 @@ DLLPush(T, U)(T* list, U* node, U* nil)
 
 struct Stack(T)
 {
-	Node!(T)* first;
+	Node!(T)* top;
 }
 
 void
-SPush(T, U)(T* stack, U* node, U* nil)
+SPush(T)(Stack!(T)* stack, Node!(T)* node, Node!(T)* nil)
 {
-	if (CheckNil(nil, stack.first))
+	if (CheckNil(nil, stack.top))
 	{
-		stack.first = node;
+		stack.top = node;
 		node.next = nil;
 	}
 	else
 	{
-		node.next = stack.first;
-		stack.first = node;
+		node.next = stack.top;
+		stack.top = node;
 	}
 }
 
-U*
-SPop(T, U)(T* stack, U* nil)
+Node!(T)*
+SPop(T)(Stack!(T)* stack, Node!(T)* nil)
 {
-	U* node = stack.first;
-	if (!CheckNil(nil, stack.first))
+	Node!(T)* node = stack.top;
+	if (!CheckNil(nil, stack.top))
 	{
-		stack.first = stack.first.next;
+		stack.top = stack.top.next;
 	}
 	return node;
 }
@@ -976,7 +976,7 @@ unittest
 		SPush(&stack, &n3, null);
 
 		u32 count = 3;
-		for (auto n = stack.first; !CheckNil(null, n); n = n.next, count -= 1)
+		for (auto n = stack.top; !CheckNil(null, n); n = n.next, count -= 1)
 		{
 			assert(n.value == count);
 		}
@@ -987,6 +987,6 @@ unittest
 			assert(n.value == count);
 		}
 
-		assert(stack.first == null);
+		assert(stack.top == null);
 	}
 }