diff --git a/Makefile b/Makefile
index 733323f..8f20888 100644
--- a/Makefile
+++ b/Makefile
@@ -6,20 +6,23 @@ ENV := env
 DEPENDS := $(ENV)/.depends
 EGG_INFO := $(subst -,_,$(PROJECT)).egg-info
 
-ifeq ($(OS),Windows_NT)
-    SYS_PYTHON := C:\\Python33\\python.exe
-    SYS_VIRTUALENV := C:\\Python33\\Scripts\\virtualenv.exe
-    BIN := $(ENV)/Scripts
+PLATFORM := $(shell python -c 'import sys; print(sys.platform)')
+
+ifneq ($(findstring win32, $(PLATFORM)), )
+	SYS_PYTHON := C:\\Python33\\python.exe
+	SYS_VIRTUALENV := C:\\Python33\\Scripts\\virtualenv.exe
+	BIN := $(ENV)/Scripts
 	EXE := .exe
 	OPEN := cmd /c start
 	# https://bugs.launchpad.net/virtualenv/+bug/449537
 	export TCL_LIBRARY=C:\\Python33\\tcl\\tcl8.5
 else
-    SYS_PYTHON := python3
-    SYS_VIRTUALENV := virtualenv
-    BIN := $(ENV)/bin
+	SYS_PYTHON := python3
+	SYS_VIRTUALENV := virtualenv
+	BIN := $(ENV)/bin
 	OPEN := open
 endif
+
 MAN := man
 SHARE := share
 
@@ -50,7 +53,7 @@ $(PIP):
 .PHONY: depends
 depends: .virtualenv $(DEPENDS) Makefile
 $(DEPENDS):
-	$(PIP) install docutils pdoc pep8 pylint nose coverage wheel
+	$(PIP) install docutils pdoc pep8 pylint nose coverage wheel mock
 	touch $(DEPENDS)  # flag to indicate dependencies are installed
 
 # Documentation ##############################################################
@@ -82,7 +85,7 @@ read: doc
 
 .PHONY: pep8
 pep8: depends
-	$(PEP8) $(PACKAGE) --ignore=E501 
+	$(PEP8) $(PACKAGE) --ignore=E501
 
 .PHONY: pylint
 pylint: depends
@@ -112,7 +115,7 @@ tests: env depends
 clean: .clean-dist .clean-test .clean-doc .clean-build
 
 .PHONY: clean-all
-clean-all: clean .clean-env 
+clean-all: clean .clean-env
 
 .PHONY: .clean-env
 .clean-env:
@@ -143,7 +146,7 @@ dist: env depends check test tests doc
 	$(PYTHON) setup.py sdist
 	$(PYTHON) setup.py bdist_wheel
 	$(MAKE) read
- 
+
 .PHONY: upload
 upload: env depends doc
 	$(PYTHON) setup.py register sdist upload