diff --git a/README.md b/README.md
index 039c926..0e9ec8f 100644
--- a/README.md
+++ b/README.md
@@ -29,7 +29,13 @@ dependencies.
 
 Usage
 ------------------------
-Download or compile Bitcoin Core v30.0 or later. Start it with:
+sv2-tp releases up to v1.0.4 can be used against Bitcoin Core v30.0.
+
+Newer releases, as well as compiling from source, require compiling Bitcoin
+Core from a recent master commit (until a future release contains the necessary
+changes). This is due to various breaking changes in the IPC interface.
+
+Start it with:
 
  ```sh
  bitcoin -m node -ipcbind=unix
diff --git a/src/ipc/capnp/mining.capnp b/src/ipc/capnp/mining.capnp
index ed01e44..97b4479 100644
--- a/src/ipc/capnp/mining.capnp
+++ b/src/ipc/capnp/mining.capnp
@@ -17,8 +17,8 @@ interface Mining $Proxy.wrap("interfaces::Mining") {
     isInitialBlockDownload @1 (context :Proxy.Context) -> (result: Bool);
     getTip @2 (context :Proxy.Context) -> (result: Common.BlockRef, hasResult: Bool);
     waitTipChanged @3 (context :Proxy.Context, currentTip: Data, timeout: Float64) -> (result: Common.BlockRef);
-    createNewBlock @4 (options: BlockCreateOptions) -> (result: BlockTemplate);
-    checkBlock @5 (block: Data, options: BlockCheckOptions) -> (reason: Text, debug: Text, result: Bool);
+    createNewBlock @4 (context :Proxy.Context, options: BlockCreateOptions) -> (result: BlockTemplate);
+    checkBlock @5 (context :Proxy.Context, block: Data, options: BlockCheckOptions) -> (reason: Text, debug: Text, result: Bool);
 }
 
 interface BlockTemplate $Proxy.wrap("interfaces::BlockTemplate") {