diff --git a/examples/python/check_dependencies.py b/examples/python/check_dependencies.py
index aa0e7d1a60..22ffdccaf7 100644
--- a/examples/python/check_dependencies.py
+++ b/examples/python/check_dependencies.py
@@ -2,16 +2,19 @@ import logging, sys, inspect
 from os.path import dirname, abspath
 from optparse import OptionParser
 
+def log_error_and_exit(error_message):
+	logging.error(error_message)
+	raise SystemExit
+
 #try to import setuptools
 try:
     from setuptools import setup, Extension
     from setuptools.command import easy_install
 except ImportError:
-    raise ImportError("""setuptools is not installed for \"""" + sys.executable + """\"
+    log_error_and_exit("""setuptools is not installed for \"""" + sys.executable + """\"
 Follow this link for installing instructions :
 https://pypi.python.org/pypi/setuptools
 make sure you use \"""" + sys.executable + """\" during the installation""")
-    raise SystemExit
 
 from pkg_resources import parse_version
 
@@ -24,10 +27,6 @@ def wrong_module(module_file, modulename):
 The python examples are not importing the """ + modulename + """ module from the sources.
 Remove the site-package that contains \"""" + module_file + """\", either manually or by using pip, and rerun this script again."""
 
-def log_error_and_exit(error_message):
-	logging.error(error_message)
-	raise SystemExit
-
 # Returns the n_th parent of file
 def n_dirname(n, file):
 	directory = file
@@ -54,6 +53,8 @@ if __name__ == '__main__':
 	
 	logging.info("Python path : " + sys.executable)
 	logging.info("Python version : " + sys.version)
+	logging.info("sys.path : " + str(sys.path))
+	ortools_project_path = n_dirname(3, abspath(inspect.getfile(inspect.currentframe())))
 
 	#try to import ortools
 	try:
@@ -65,22 +66,11 @@ if __name__ == '__main__':
 	#check if we're using ortools from the sources or it's binded by pypi's module
 	ortools_module_file = inspect.getfile(ortools)
 	ortools_module_path = n_dirname(3, ortools_module_file)
-	ortools_project_path = n_dirname(3, abspath(inspect.getfile(inspect.currentframe())))
-	try:
-		if(ortools_module_path == ortools_project_path):
-			logging.info("Good! The python examples are importing the ortools module from the sources. The imported module is : " + inspect.getfile(ortools))
-		else:
-			raise Exception
-	except (Exception):
+	if(ortools_module_path == ortools_project_path):
+		logging.info("Or-tools is imported from : " + ortools_module_file)
+	else:
 		log_error_and_exit(wrong_module(ortools_module_file, "ortools"))
 
-	#try to import protobuf
-	try:
-		import google.protobuf
-		logging.info("Protobuf is imported from " + inspect.getfile(google.protobuf))
-	except ImportError:
-	    log_error_and_exit(notinstalled("protobuf"))
-
 	# Check if python can load the libraries' modules
 	# this is useful when the library architecture is not compatbile with the python executable,
 	# or when the library's dependencies are not available or not compatible.
@@ -89,4 +79,20 @@ if __name__ == '__main__':
 	from ortools.algorithms import _pywrapknapsack_solver
 	from ortools.graph import _pywrapgraph
 
+	#try to import protobuf
+	try:
+		import google.protobuf
+	except ImportError:
+	    log_error_and_exit(notinstalled("protobuf"))
 
+	#check if we're using protobuf from the sources or it's binded by pypi's module
+	protobuf_module_file = inspect.getfile(google.protobuf)
+	protobuf_module_path = n_dirname(7, protobuf_module_file)
+	if(protobuf_module_path == ortools_project_path):
+		logging.info("Protobuf is imported from : " + protobuf_module_file)
+	else:
+		log_error_and_exit(wrong_module(protobuf_module_file, "protobuf"))
+
+	#Check if the protobuf modules were successfully generated
+	from google.protobuf import descriptor as _descriptor
+	from google.protobuf import descriptor_pb2
\ No newline at end of file
diff --git a/makefiles/Makefile.python.mk b/makefiles/Makefile.python.mk
index 65a1a9b60b..5d366e6e28 100755
--- a/makefiles/Makefile.python.mk
+++ b/makefiles/Makefile.python.mk
@@ -1,3 +1,5 @@
+.PHONY : install_python_modules
+
 # Python support using SWIG
 
 # Detect python3
@@ -23,11 +25,18 @@ ifeq ("$(PYTHON_VERSION)","35")
   SWIG_PYTHON3_FLAG=-py3 -DPY3
 endif
 
-
 OR_TOOLS_PYTHONPATH = $(OR_ROOT_FULL)$Ssrc$(CPSEP)$(OR_ROOT_FULL)$Sdependencies$Ssources$Sprotobuf-$(PROTOBUF_TAG)$Spython
 
+ifeq ($(SYSTEM),win)
+  PYTHON_EXECUTABLE = $(WINDOWS_PYTHON_PATH)$Spython
+  SET_PYTHONPATH = @set PYTHONPATH=$(OR_TOOLS_PYTHONPATH) &&
+else #UNIX
+  PYTHON_EXECUTABLE = python$(UNIX_PYTHON_VER)
+  SET_PYTHONPATH = @PYTHONPATH=$(OR_TOOLS_PYTHONPATH)
+endif
+
 # Main target
-python: pyinit pycp pyalgorithms pygraph pylp
+python: install_python_modules pyinit pycp pyalgorithms pygraph pylp
 
 # Clean target
 clean_python:
@@ -51,6 +60,15 @@ clean_python:
 	-$(DEL) $(LIB_DIR)$S_pywrap*.$(SWIG_LIB_SUFFIX)
 	-$(DEL) $(OBJ_DIR)$Sswig$S*python_wrap.$O
 
+install_python_modules: dependencies/sources/protobuf-3.0.0/python/google/protobuf/descriptor_pb2.py
+
+dependencies/sources/protobuf-3.0.0/python/google/protobuf/descriptor_pb2.py: \
+dependencies/sources/protobuf-$(PROTOBUF_TAG)/python/setup.py
+ifeq ("$(SYSTEM)", "win")
+	copy dependencies$Sinstall$Sbin$Sprotoc.exe dependencies$Ssources$Sprotobuf-$(PROTOBUF_TAG)$Ssrc
+endif
+	cd dependencies$Ssources$Sprotobuf-$(PROTOBUF_TAG)$Spython && $(PYTHON_EXECUTABLE) setup.py build
+
 pyinit: $(GEN_DIR)$Sortools$S__init__.py
 
 $(GEN_DIR)$Sortools$S__init__.py:
@@ -206,12 +224,7 @@ endif
 
 rpy: $(LIB_DIR)/_pywraplp.$(SWIG_LIB_SUFFIX) $(LIB_DIR)/_pywrapcp.$(SWIG_LIB_SUFFIX) $(LIB_DIR)/_pywrapgraph.$(SWIG_LIB_SUFFIX) $(LIB_DIR)/_pywrapknapsack_solver.$(SWIG_LIB_SUFFIX) $(EX)
 	@echo Running $(EX)
-ifeq ($(SYSTEM),win)
-	@set PYTHONPATH=$(OR_TOOLS_PYTHONPATH) && $(WINDOWS_PATH_TO_PYTHON)$Spython $(EX) $(ARGS)
-else
-	@PYTHONPATH=$(OR_TOOLS_PYTHONPATH) python$(PYTHON_VERSION) $(EX) $(ARGS)
-endif
-
+	$(SET_PYTHONPATH) $(PYTHON_EXECUTABLE) $(EX) $(ARGS)
 
 # Build stand-alone archive file for redistribution.
 
@@ -301,15 +314,15 @@ endif
 endif
 
 pypi_upload: pypi_archive
-	@echo Uploading Pypi module for python$(PYTHON_VERSION).
+	@echo Uploading Pypi module for $(PYTHON_EXECUTABLE).
 ifeq ($(SYSTEM),win)
 	set VS90COMNTOOLS=$(VS$(VS_COMTOOLS)COMNTOOLS)
-	cd temp\ortools && $(WINDOWS_PATH_TO_PYTHON)\python setup.py register bdist_egg bdist_wheel bdist_wininst upload
+	cd temp\ortools && $(PYTHON_EXECUTABLE) setup.py register bdist_egg bdist_wheel bdist_wininst upload
 else
   ifeq ($(PLATFORM),MACOSX)
-	cd temp/ortools && python$(PYTHON_VERSION) setup.py register bdist_egg bdist_wheel upload
+	cd temp/ortools && $(PYTHON_EXECUTABLE) setup.py register bdist_egg bdist_wheel upload
   else
-	cd temp/ortools && python$(PYTHON_VERSION) setup.py register bdist_egg upload
+	cd temp/ortools && $(PYTHON_EXECUTABLE) setup.py register bdist_egg upload
   endif
 endif
 
diff --git a/makefiles/Makefile.third_party.unix b/makefiles/Makefile.third_party.unix
index af2bf2b87e..529b2a1b87 100755
--- a/makefiles/Makefile.third_party.unix
+++ b/makefiles/Makefile.third_party.unix
@@ -468,11 +468,6 @@ clean_third_party:
 # Create Makefile.local
 makefile_third_party: Makefile.local
 
-# Install python modules
-install_python_modules: install_protobuf
-	cd dependencies/sources/protobuf-$(PROTOBUF_TAG)/python && python$(PYTHON_VERSION) setup.py build
-	cd dependencies/sources/protobuf-$(PROTOBUF_TAG)/python && python$(PYTHON_VERSION) setup.py install --user
-
 Makefile.local:
 	@echo Generating Makefile.local
 	@echo UNIX_PYTHON_VER = $(DETECTED_PYTHON_VERSION) > Makefile.local
diff --git a/makefiles/Makefile.third_party.win b/makefiles/Makefile.third_party.win
index 79f091f450..588754dd66 100755
--- a/makefiles/Makefile.third_party.win
+++ b/makefiles/Makefile.third_party.win
@@ -431,12 +431,6 @@ clean_third_party:
 # Create Makefile.local
 makefile_third_party: Makefile.local
 
-# Install python modules
-install_python_modules: install_protobuf
-	copy dependencies\install\bin\protoc.exe dependencies\sources\protobuf-$(PROTOBUF_TAG)\src
-	cd dependencies\sources\protobuf-$(PROTOBUF_TAG)/python && $(WINDOWS_PATH_TO_PYTHON)\\python.exe setup.py build
-	cd dependencies\sources\protobuf-$(PROTOBUF_TAG)/python && $(WINDOWS_PATH_TO_PYTHON)\\python.exe setup.py install --user
-
 Makefile.local:
 	@echo Generating Makefile.local
 	@echo WINDOWS_ZLIB_DIR = $(OR_ROOT_FULL)\\dependencies\\install> Makefile.local
diff --git a/tools/check_python_deps.py b/tools/check_python_deps.py
index 669d837da9..1e147d477b 100644
--- a/tools/check_python_deps.py
+++ b/tools/check_python_deps.py
@@ -7,24 +7,24 @@ try:
     from setuptools.command import easy_install
 except ImportError:
     raise ImportError("""setuptools is not installed for \"""" + sys.executable + """\"
-Follow this link for installing instructions :
+Please follow this link for installing instructions :
 https://pypi.python.org/pypi/setuptools
 make sure you use \"""" + sys.executable + """\" during the installation""")
     raise SystemExit
 
 from pkg_resources import parse_version
 
-required_ortools_version = "VVVV"
-required_protobuf_version = "PROTOBUF_TAG"
+required_ortools_version = "5.0.3919"
+required_protobuf_version = "3.0.0"
 
 def notinstalled(modulename):
 	return modulename + """ is not installed for \"""" + sys.executable + """\"
-Run \"""" + sys.executable + """ setup.py install --user\" to install it"""
+Please run \"""" + str(sys.executable) + """ setup.py install --user\""""
 
 def wrong_version(module, modulename, required_version, installed_version):
 	return """You are using """ + modulename + """-""" + installed_version + """ : """ + inspect.getfile(module) + """, while the required version is : """ + required_version + """
-Run \"""" + sys.executable + """ setup.py install --user\" to upgrade.
-If the problem persists, remove the site-package that contains \"""" + inspect.getfile(module) + """\". You can do so either manually or by using pip."""
+Run \"""" + str(sys.executable) + """ setup.py install --user\" to upgrade.
+If the problem persists, then \"""" + inspect.getfile(module) + """\" is binding the newely installed version of """ + modulename + """. Remove it manually or by using pip."""
 
 def log_error_and_exit(error_message):
 	logging.error(error_message)