diff --git a/FindIonobase.cmake b/FindIonobase.cmake
index 0645d47..d527a52 100644
--- a/FindIonobase.cmake
+++ b/FindIonobase.cmake
@@ -12,7 +12,7 @@ if(NOT IONOBASE_IS_EXTERNAL_PROJECT)
   endif()
   find_path(
     IONOBASE_INCLUDE_DIRS
-    NAMES ionobase/interchfor.hpp
+    NAMES ionobase/interchfor.h
     PATHS ${_search_paths})
 
   set(_search_paths "")