diff --git a/build/unix/module.modulemap b/build/unix/module.modulemap
index 3854278319ede..b075e20072c9d 100644
--- a/build/unix/module.modulemap
+++ b/build/unix/module.modulemap
@@ -1,14 +1,6 @@
-// This can be used in C mode. It cannot go in ROOT_Type because ThreadLocalStorage.h
-// uses kFALSE and kTRUE, which come from Rtypes.h causing a cycle.
-// FIXME: This should be separated because it introduces header dependency
-// libThread->libCore->libThread. We should figure out a way to implement it in
-// a more reasonable way.
-module ThreadLocalStorage {
-  header "ThreadLocalStorage.h"
-  export *
-}
 // These can be used in C mode.
 module ROOT_Types {
+  module "ThreadLocalStorage.h" { header "ThreadLocalStorage.h" export * }
   module "RtypesCore.h" { header "RtypesCore.h" export * }
   module "ESTLType.h" { header "ESTLType.h" export * }
   // FIXME: This module should contain only header files with types.
diff --git a/core/thread/inc/ThreadLocalStorage.h b/core/thread/inc/ThreadLocalStorage.h
index 109943b613c5a..ad68e115aa653 100644
--- a/core/thread/inc/ThreadLocalStorage.h
+++ b/core/thread/inc/ThreadLocalStorage.h
@@ -58,7 +58,7 @@
 #include <stddef.h>
 
 #ifdef __cplusplus
-#include "Rtypes.h"
+#include "RtypesCore.h"
 #endif
 
 #include "RConfig.h"