diff --git a/repertory/librepertory/src/file_manager/cache_size_mgr.cpp b/repertory/librepertory/src/file_manager/cache_size_mgr.cpp
index 598b5be3..3117d464 100644
--- a/repertory/librepertory/src/file_manager/cache_size_mgr.cpp
+++ b/repertory/librepertory/src/file_manager/cache_size_mgr.cpp
@@ -29,6 +29,11 @@
 
 namespace repertory {
 // clang-format off
+E_SIMPLE2(invalid_cache_size, warn, true,
+  std::uint64_t, cache_size, sz, E_FROM_UINT64,
+  std::uint64_t, reduce, rd, E_FROM_UINT64 
+);
+
 E_SIMPLE2(max_cache_size_reached, warn, true,
   std::uint64_t, cache_size, sz, E_FROM_UINT64,
   std::uint64_t, max_cache_size, max, E_FROM_UINT64 
@@ -93,7 +98,7 @@ auto cache_size_mgr::shrink(std::uint64_t size) -> api_error {
   if (cache_size_ >= size) {
     cache_size_ -= size;
   } else {
-    // TODO raise warning
+    event_system::instance().raise<max_cache_size_reached>(cache_size_, size);
     cache_size_ = 0U;
   }