diff --git a/tests/parser-cases/foo.bar.thrift b/tests/parser-cases/foo.bar.thrift
new file mode 100644
index 0000000..d9b3174
--- /dev/null
+++ b/tests/parser-cases/foo.bar.thrift
@@ -0,0 +1 @@
+include "foo/bar.thrift"
\ No newline at end of file
diff --git a/tests/parser-cases/foo/bar.thrift b/tests/parser-cases/foo/bar.thrift
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_parser.py b/tests/test_parser.py
index cb51a71..a0388dc 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -40,6 +40,12 @@ def test_include():
     assert thrift.datetime == 1422009523
 
 
+def test_include_conflict():
+    with pytest.raises(ThriftParserError) as excinfo:
+        load('parser-cases/foo.bar.thrift', module_name='foo.bar_thrift')
+    assert 'Module name conflict between "parser-cases/foo.bar.thrift" and "parser-cases/foo/bar.thrift"' == str(excinfo.value)
+
+
 def test_cpp_include():
     load('parser-cases/cpp_include.thrift')
 
diff --git a/thriftpy2/parser/__init__.py b/thriftpy2/parser/__init__.py
index 16bb8fa..856941a 100644
--- a/thriftpy2/parser/__init__.py
+++ b/thriftpy2/parser/__init__.py
@@ -41,16 +41,20 @@ def load(path,
     # add sub modules to sys.modules recursively
     if real_module:
         sys.modules[module_name] = thrift
-        include_thrifts = thrift.__thrift_meta__["includes"][:]
+        include_thrifts = list(zip(thrift.__thrift_meta__["includes"][:],
+                                   thrift.__thrift_meta__["sub_modules"][:]))
         while include_thrifts:
             include_thrift = include_thrifts.pop()
-            lost_sub_modules = [
-                m for m in thrift.__thrift_meta__["sub_modules"] if m not in sys.modules
-            ]
-            for module in lost_sub_modules:
-                sys.modules[module.__name__] = include_thrift
-            if include_thrift.__name__ not in sys.modules:
-                include_thrifts.extend(include_thrift.__thrift_meta__["includes"])
+            registered_thrift = sys.modules.get(include_thrift[1].__name__)
+            if registered_thrift is None:
+                sys.modules[include_thrift[1].__name__] = include_thrift[0]
+                include_thrifts.extend(include_thrift[0].__thrift_meta__["includes"])
+            else:
+                if registered_thrift.__thrift_file__ != include_thrift[0].__thrift_file__:
+                    raise ThriftParserError(
+                        'Module name conflict between "%s" and "%s"' %
+                        (registered_thrift.__thrift_file__, include_thrift[0].__thrift_file__)
+                    )
     return thrift
 
 
diff --git a/thriftpy2/parser/parser.py b/thriftpy2/parser/parser.py
index 441f401..be44975 100644
--- a/thriftpy2/parser/parser.py
+++ b/thriftpy2/parser/parser.py
@@ -62,15 +62,8 @@ def p_include(p):
     for include_dir in replace_include_dirs:
         path = os.path.join(include_dir, p[2])
         if os.path.exists(path):
-            child_path = os.path.normpath(
-                os.path.dirname(str(thrift.__name__).replace("_thrift", "").replace(".", os.sep)) + os.sep + p[2])
-
-            child_path = child_path.lstrip(os.sep)
-
-            child_module_name = str(
-                child_path).replace(os.sep,
-                                    ".").replace(
-                ".thrift", "_thrift")
+            child_rel_path = os.path.relpath(str(path), os.path.dirname(thrift.__thrift_file__))
+            child_module_name = str(child_rel_path).replace(os.sep, ".").replace(".thrift", "_thrift")
 
             child = parse(path, module_name=child_module_name)
             setattr(thrift, str(child.__name__).replace("_thrift", ""), child)