diff --git a/tests/GenerateSipBindings/CMakeLists.txt b/tests/GenerateSipBindings/CMakeLists.txt
index c223bce..151db9f 100644
--- a/tests/GenerateSipBindings/CMakeLists.txt
+++ b/tests/GenerateSipBindings/CMakeLists.txt
@@ -1,47 +1,52 @@
 cmake_minimum_required(VERSION 3.2)
 
 project(GenerateSipBindings)
 
 find_package(Qt5Core REQUIRED)
 
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 set(CMAKE_INCLUDE_CURRENT_DIR_IN_INTERFACE ON)
 
 set(CMAKE_CXX_STANDARD 14)
 
 add_library(ExternalLib SHARED external_lib.cpp)
 target_link_libraries(ExternalLib PUBLIC Qt5::Core)
 target_compile_features(ExternalLib PUBLIC cxx_nullptr)
 
-add_library(CppLib SHARED cpplib.cpp)
+add_library(CppLib SHARED
+  cpplib.cpp
+  subdir/subdirfile.cpp
+)
 target_link_libraries(CppLib
     PUBLIC Qt5::Core
     PRIVATE ExternalLib
 )
 target_compile_features(CppLib PUBLIC cxx_nullptr)
+target_include_directories(CppLib PUBLIC subdir)
 
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../../find-modules)
 
 find_package(PythonModuleGeneration REQUIRED)
 
 ecm_generate_python_binding(
   TARGET ExternalLib
   PYTHONNAMESPACE PyTest
   MODULENAME ExternalLib
   SIP_DEPENDS
     QtCore/QtCoremod.sip
   HEADERS
     external_lib.h
 )
 
 ecm_generate_python_binding(
   TARGET CppLib
   PYTHONNAMESPACE PyTest
   MODULENAME CppLib
   RULES_FILE "${CMAKE_CURRENT_SOURCE_DIR}/rules_SipTest.py"
   SIP_DEPENDS
     QtCore/QtCoremod.sip
   HEADERS
     cpplib.h
+    subdir/subdirfile.h
 )
diff --git a/tests/GenerateSipBindings/subdir/subdirfile.cpp b/tests/GenerateSipBindings/subdir/subdirfile.cpp
new file mode 100644
index 0000000..d874243
--- /dev/null
+++ b/tests/GenerateSipBindings/subdir/subdirfile.cpp
@@ -0,0 +1,7 @@
+
+#include "subdirfile.h"
+
+int SubdirObject::mul(int a, int b)
+{
+  return a * b;
+}
diff --git a/tests/GenerateSipBindings/subdir/subdirfile.h b/tests/GenerateSipBindings/subdir/subdirfile.h
new file mode 100644
index 0000000..5fd18db
--- /dev/null
+++ b/tests/GenerateSipBindings/subdir/subdirfile.h
@@ -0,0 +1,8 @@
+
+#pragma once
+
+class SubdirObject
+{
+public:
+    int mul(int a, int b);
+};
diff --git a/tests/GenerateSipBindings/testscript.py b/tests/GenerateSipBindings/testscript.py
index 9e12bd1..e79706b 100644
--- a/tests/GenerateSipBindings/testscript.py
+++ b/tests/GenerateSipBindings/testscript.py
@@ -1,120 +1,123 @@
 
 import sys
 
 from PyQt5 import QtCore
 
 sys.path.append(sys.argv[1])
 
 import PyTest.CppLib
 
 mo = PyTest.CppLib.MyObject()
 
 assert(mo.addThree(39) == 42)
 
 assert(mo.addThree([38, 39, 40]) == [41, 42, 43])
 
 assert(mo.addThree("SomeString") == "DefaultSomeStringThree")
 
 assert(mo.findNeedle(["One", "Two", "Three"], "Two") == 1)
 assert(mo.findNeedle(["One", "Two", "Three"], "Four") == -1)
 assert(mo.findNeedle(["One", "Two", "Three"], "Th") == 2)
 assert(mo.findNeedle(["One", "Two", "Three"], "Th", QtCore.Qt.MatchExactly) == -1)
 
 assert(mo.const_parameters(30) == 15)
 assert(mo.const_parameters(30, mo) == 10)
 
 assert(mo.qtEnumTest(QtCore.Qt.MatchContains | QtCore.Qt.MatchStartsWith) == 3)
 assert(mo.localEnumTest(PyTest.CppLib.MyObject.Val2) == 2)
 
 lfd = PyTest.CppLib.LocalFwdDecl(18)
 
 assert(mo.localFwdDecl(lfd) == 18)
 
 import PyTest.ExternalLib
 
 efd = PyTest.ExternalLib.ExternalFwdDecl(18)
 
 assert(mo.externalFwdDecl(efd) == 18)
 
 assert(mo.localListDecl([1, 5, 7]) == 13)
 
 lfdl = [PyTest.CppLib.LocalFwdDecl(3), PyTest.CppLib.LocalFwdDecl(6)]
 
 assert(mo.localDeclListDecl(lfdl) == 9)
 
 #
 # Verify that an enum with attributes can be read.
 #
 assert(PyTest.CppLib.Foo == 0)
 assert(PyTest.CppLib.Bar == 2)
 
 class Reactor(QtCore.QObject):
     def __init__(self, obj):
         QtCore.QObject.__init__(self)
         self.gotPrivateSlotCalledSignal = False
         self.gotProtectedSlotCalledSignal = False
         self.gotPublicSlotCalledSignal = False
 
         obj.privateSlotCalled.connect(self.react_to_privateSlotCalled)
         obj.protectedSlotCalled.connect(self.react_to_protectedSlotCalled)
         obj.publicSlotCalled.connect(self.react_to_publicSlotCalled)
 
     def react_to_privateSlotCalled(self):
         self.gotPrivateSlotCalledSignal = True
 
     def react_to_protectedSlotCalled(self):
         self.gotProtectedSlotCalledSignal = True
 
     def react_to_publicSlotCalled(self):
         self.gotPublicSlotCalledSignal = True
 
 class Emitter(QtCore.QObject):
     privateTrigger = QtCore.pyqtSignal()
     protectedTrigger = QtCore.pyqtSignal()
     publicTrigger = QtCore.pyqtSignal()
 
     def __init__(self, obj):
         QtCore.QObject.__init__(self)
         self.privateTrigger.connect(obj.privateSlot1)
         self.protectedTrigger.connect(obj.protectedSlot1)
         self.publicTrigger.connect(obj.publicSlot1)
 
     def emitSignalForPublic(self):
         self.publicTrigger.emit()
 
     def emitSignalForPrivate(self):
         self.privateTrigger.emit()
 
     def emitSignalForProtected(self):
         self.protectedTrigger.emit()
 
 e = Emitter(mo)
 
 r = Reactor(mo)
 
 assert(not r.gotPrivateSlotCalledSignal)
 assert(not r.gotProtectedSlotCalledSignal)
 assert(not r.gotPublicSlotCalledSignal)
 
 e.emitSignalForPrivate()
 
 assert(r.gotPrivateSlotCalledSignal)
 
 e.emitSignalForProtected()
 
 assert(r.gotProtectedSlotCalledSignal)
 
 e.emitSignalForPublic()
 
 assert(r.gotPublicSlotCalledSignal)
 
 assert(PyTest.CppLib.SomeNS.EnumValueOne == 1)
 assert(PyTest.CppLib.SomeNS.EnumValueTwo == 2)
 
 assert(PyTest.CppLib.SomeNS.useEnum() == 1.0)
 assert(PyTest.CppLib.SomeNS.useEnum(PyTest.CppLib.SomeNS.EnumValueOne) == 1.0)
 assert(PyTest.CppLib.SomeNS.useEnum(PyTest.CppLib.SomeNS.EnumValueTwo) == 2.0)
 
 assert(PyTest.CppLib.SomeNS.customMethod([2, 3, 5]) == 10)
 
 assert(PyTest.CppLib.anotherCustomMethod([2, 3, 5]) == 52)
+
+sdo = PyTest.CppLib.SubdirObject()
+assert(sdo.mul(5, 6) == 30)