diff --git a/library/modules/std/objc_block.sx b/library/modules/std/objc_block.sx
index 3c0b031..d9aaeb2 100644
--- a/library/modules/std/objc_block.sx
+++ b/library/modules/std/objc_block.sx
@@ -52,70 +52,14 @@ __sx_block_descriptor : BlockDescriptor = .{
     size = 48,
 };
 
-// Per-signature invoke trampolines. Each one reads sx_env + sx_fn from
-// its block_self argument and tail-calls the closure through a typed
-// fn-ptr cast. One per Apple block signature we support.
-//
-// Adding a new signature: write a `__block_invoke_<sig>` trampoline
-// matching the closure's calling convention and an
-// `impl Into(Block) for Closure(<sig>)` that points its `invoke`
-// field at the trampoline. The `xx closure : Block` cast finds the
-// impl via `Into` protocol dispatch.
-//
-// Signature: `void (^)(void)` — no args, no return. The single most
-// common Apple block shape (UIView animation bodies, dispatch_async, etc).
-__block_invoke_void :: (block_self: *Block) callconv(.c) {
-    // `sx_fn` is the closure trampoline — an sx-side function with the
-    // implicit __sx_ctx at slot 0 and env at slot 1. We're a callconv(.c)
-    // entry, so the call site needs ctx prepended; the typed fn-pointer
-    // type stays default-conv to enable that.
-    typed_fn : (*void) -> void = xx block_self.sx_fn;
-    typed_fn(block_self.sx_env);
-}
-
-impl Into(Block) for Closure() -> void {
-    convert :: (self: Closure() -> void) -> Block {
-        .{
-            isa = @_NSConcreteStackBlock,
-            flags = 0,
-            reserved = 0,
-            invoke = xx @__block_invoke_void,
-            descriptor = xx @__sx_block_descriptor,
-            sx_env = self.env,
-            sx_fn = self.fn_ptr,
-        };
-    }
-}
-
-// Signature: `void (^)(BOOL)` — UIView animation completion handlers and
-// similar one-arg-bool callbacks.
-__block_invoke_bool :: (block_self: *Block, arg0: bool) callconv(.c) {
-    typed_fn : (*void, bool) -> void = xx block_self.sx_fn;
-    typed_fn(block_self.sx_env, arg0);
-}
-
-impl Into(Block) for Closure(bool) -> void {
-    convert :: (self: Closure(bool) -> void) -> Block {
-        .{
-            isa = @_NSConcreteStackBlock,
-            flags = 0,
-            reserved = 0,
-            invoke = xx @__block_invoke_bool,
-            descriptor = xx @__sx_block_descriptor,
-            sx_env = self.env,
-            sx_fn = self.fn_ptr,
-        };
-    }
-}
-
-// Generic impl: covers any closure shape not handled by the
-// hand-rolled per-signature impls above. The compiler
+// Single generic impl covers every closure shape. The compiler
 // monomorphises this body per call shape; inside each mono,
 // `$args` is the bound pack of arg types and `$R` is the bound
 // return type. The `#insert` evaluates `build_block_convert` at
 // comptime and substitutes the resulting source — a nested
 // `callconv(.c)` trampoline + the Block literal that points its
-// `invoke` slot at it.
+// `invoke` slot at it. One impl in stdlib replaces every per-
+// signature hand-rolled `__block_invoke_*` + `Into(Block)` pair.
 impl Into(Block) for Closure(..$args) -> $R {
     convert :: (self: Closure(..$args) -> $R) -> Block {
         #insert build_block_convert($args, $R);