diff --git a/src/a2a3/platform/sim/host/CMakeLists.txt b/src/a2a3/platform/sim/host/CMakeLists.txt
index eb1d40a360..7006cc54c4 100644
--- a/src/a2a3/platform/sim/host/CMakeLists.txt
+++ b/src/a2a3/platform/sim/host/CMakeLists.txt
@@ -95,6 +95,10 @@ target_compile_options(host_runtime
 # Platform name baked into the shared get_platform() impl in
 # src/common/platform/shared/host/platform_compile_info.cpp.
 target_compile_definitions(host_runtime PRIVATE SIMPLER_PLATFORM_NAME="a2a3sim")
+set_source_files_properties(
+    "${CMAKE_CURRENT_SOURCE_DIR}/../../../../common/platform/shared/host/platform_compile_info.cpp"
+    PROPERTIES COMPILE_DEFINITIONS SIMPLER_CACHE_FIRST_PR_TEST=1
+)
 
 # Include directories
 target_include_directories(host_runtime