diff --git a/src/host/pico_stdio/CMakeLists.txt b/src/host/pico_stdio/CMakeLists.txt
index 82a31483..e05bfb91 100644
--- a/src/host/pico_stdio/CMakeLists.txt
+++ b/src/host/pico_stdio/CMakeLists.txt
@@ -16,5 +16,7 @@ if (NOT TARGET pico_stdio)
     endfunction()
     function(pico_enable_stdio_semihosting)
     endfunction()
+    function(pico_enable_stdio_rtt)
+    endfunction()
 endif()