diff --git a/src/host/pico_runtime/CMakeLists.txt b/src/host/pico_runtime/CMakeLists.txt
index dd4d6717..be809c6d 100644
--- a/src/host/pico_runtime/CMakeLists.txt
+++ b/src/host/pico_runtime/CMakeLists.txt
@@ -1,5 +1,7 @@
 pico_add_library(pico_runtime)
 
+target_sources(pico_runtime INTERFACE ${CMAKE_CURRENT_LIST_DIR}/runtime.c)
+
 target_include_directories(pico_runtime_headers SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
 
 pico_mirrored_target_link_libraries(pico_runtime INTERFACE