diff --git a/CMakeLists.txt b/CMakeLists.txt
index 43eb97d..f96f1d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,7 +63,7 @@ if (DEBUG_ON_PICO)
             OUTPUT_NAME "debugprobe_on_pico2"
         )
     else ()
-        error("Unsupported board ${PICO_BOARD}" PICO_BOARD)
+        message(SEND_ERROR "Unsupported board ${PICO_BOARD}")
     endif ()
 endif ()
 
diff --git a/README.md b/README.md
index dc0691e..83b9263 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ cd debugprobe
 ```
 Initialize and update the submodules:
 ```
- git submodule update --init
+ git submodule update --init --recursive
 ```
 Then create and switch to the build directory:
 ```