diff --git a/include/cppast/cpp_function_types.hpp b/include/cppast/cpp_function_type.hpp
similarity index 97%
rename from include/cppast/cpp_function_types.hpp
rename to include/cppast/cpp_function_type.hpp
index 656c67e..c5a88f9 100644
--- a/include/cppast/cpp_function_types.hpp
+++ b/include/cppast/cpp_function_type.hpp
@@ -2,8 +2,8 @@
 // This file is subject to the license terms in the LICENSE file
 // found in the top-level directory of this distribution.
 
-#ifndef CPPAST_CPP_FUNCTION_TYPES_HPP_INCLUDED
-#define CPPAST_CPP_FUNCTION_TYPES_HPP_INCLUDED
+#ifndef CPPAST_CPP_FUNCTION_TYPE_HPP_INCLUDED
+#define CPPAST_CPP_FUNCTION_TYPE_HPP_INCLUDED
 
 #include <cppast/cpp_type.hpp>
 
@@ -204,4 +204,4 @@ namespace cppast
     };
 } // namespace cppast
 
-#endif // CPPAST_CPP_FUNCTION_TYPES_HPP_INCLUDED
+#endif // CPPAST_CPP_FUNCTION_TYPE_HPP_INCLUDED
diff --git a/src/cpp_type.cpp b/src/cpp_type.cpp
index df6f715..3d9007a 100644
--- a/src/cpp_type.cpp
+++ b/src/cpp_type.cpp
@@ -7,7 +7,7 @@
 #include <cppast/cpp_array_type.hpp>
 #include <cppast/cpp_entity.hpp>
 #include <cppast/cpp_entity_kind.hpp>
-#include <cppast/cpp_function_types.hpp>
+#include <cppast/cpp_function_type.hpp>
 
 using namespace cppast;