diff --git a/repos/base-fiasco/src/core/include/ipc_pager.h b/repos/base-fiasco/src/core/include/ipc_pager.h
index 62d699af4f..ace21ed4e7 100644
--- a/repos/base-fiasco/src/core/include/ipc_pager.h
+++ b/repos/base-fiasco/src/core/include/ipc_pager.h
@@ -19,9 +19,11 @@
 #include <base/ipc.h>
 #include <base/stdint.h>
 #include <base/native_types.h>
-#include <fiasco/thread_helper.h>
 #include <util/touch.h>
 
+/* base-internal includes */
+#include <base/internal/fiasco_thread_helper.h>
+
 /* Fiasco includes */
 namespace Fiasco {
 #include <l4/sys/types.h>
diff --git a/repos/base-fiasco/src/core/include/util.h b/repos/base-fiasco/src/core/include/util.h
index 28bebf09e4..5d96bba21f 100644
--- a/repos/base-fiasco/src/core/include/util.h
+++ b/repos/base-fiasco/src/core/include/util.h
@@ -21,7 +21,9 @@
 #include <base/printf.h>
 #include <rm_session/rm_session.h>
 #include <util/touch.h>
-#include <fiasco/thread_helper.h>
+
+/* base-internal includes */
+#include <base/internal/fiasco_thread_helper.h>
 
 /* Fiasco includes */
 namespace Fiasco {
diff --git a/repos/base-fiasco/src/core/platform.cc b/repos/base-fiasco/src/core/platform.cc
index 3570f44d00..e0bc786e88 100644
--- a/repos/base-fiasco/src/core/platform.cc
+++ b/repos/base-fiasco/src/core/platform.cc
@@ -19,7 +19,7 @@
 
 /* base-internal includes */
 #include <base/internal/crt0.h>
-#include <fiasco/thread_helper.h>
+#include <base/internal/fiasco_thread_helper.h>
 
 /* core includes */
 #include <core_parent.h>
diff --git a/repos/base-fiasco/src/core/spec/x86/platform_x86.cc b/repos/base-fiasco/src/core/spec/x86/platform_x86.cc
index 440bcf60df..9298fe2fd4 100644
--- a/repos/base-fiasco/src/core/spec/x86/platform_x86.cc
+++ b/repos/base-fiasco/src/core/spec/x86/platform_x86.cc
@@ -11,7 +11,7 @@
  * under the terms of the GNU General Public License version 2.
  */
 
-#include <fiasco/thread_helper.h>
+#include <base/internal/fiasco_thread_helper.h>
 
 #include "platform.h"
 #include "util.h"
diff --git a/repos/base-fiasco/include/fiasco/thread_helper.h b/repos/base-fiasco/src/include/base/internal/fiasco_thread_helper.h
similarity index 100%
rename from repos/base-fiasco/include/fiasco/thread_helper.h
rename to repos/base-fiasco/src/include/base/internal/fiasco_thread_helper.h