diff --git a/test/02_test/cibuildwheel_test.py b/test/02_test/cibuildwheel_test.py
index 9ec4fa56..e70b0172 100644
--- a/test/02_test/cibuildwheel_test.py
+++ b/test/02_test/cibuildwheel_test.py
@@ -6,11 +6,13 @@ def test():
     project_dir = os.path.dirname(__file__)
     # set up the environment
     env = os.environ.copy()
-    env['CIBW_TEST_REQUIRES'] = 'nose'
-    # the 'false ||' bit is to ensure this command runs in a shell on
-    # mac/linux.
-    env['CIBW_TEST_COMMAND'] = 'false || nosetests {project}/test'
-    env['CIBW_TEST_COMMAND_WINDOWS'] = 'nosetests {project}/test'
+    env.update({
+        'CIBW_TEST_REQUIRES': 'nose',
+        # the 'false ||' bit is to ensure this command runs in a shell on
+        # mac/linux.
+        'CIBW_TEST_COMMAND': 'false || nosetests {project}/test',
+        'CIBW_TEST_COMMAND_WINDOWS': 'nosetests {project}/test',
+    })
 
     # build & test the wheels
     subprocess.check_call([sys.executable, '-m', 'cibuildwheel', project_dir], env=env)
diff --git a/test/03_before_build/cibuildwheel_test.py b/test/03_before_build/cibuildwheel_test.py
index 5ce69243..cbf902b4 100644
--- a/test/03_before_build/cibuildwheel_test.py
+++ b/test/03_before_build/cibuildwheel_test.py
@@ -8,8 +8,10 @@ def test():
     env = os.environ.copy()
     # write python version information to a temporary file, this is checked
     # in setup.py
-    env['CIBW_BEFORE_BUILD'] = "python -c \"import sys; open('/tmp/pythonversion.txt', 'w').write(sys.version)\" && python -c \"import sys; open('/tmp/pythonexecutable.txt', 'w').write(sys.executable)\""
-    env['CIBW_BEFORE_BUILD_WINDOWS'] = "python -c \"import sys; open('c:\\pythonversion.txt', 'w').write(sys.version)\" && python -c \"import sys; open('c:\\pythonexecutable.txt', 'w').write(sys.executable)\""
+    env.update({
+        'CIBW_BEFORE_BUILD': '''python -c "import sys; open('/tmp/pythonversion.txt', 'w').write(sys.version)" && python -c "import sys; open('/tmp/pythonexecutable.txt', 'w').write(sys.executable)"''',
+        'CIBW_BEFORE_BUILD_WINDOWS': '''python -c "import sys; open('c:\\pythonversion.txt', 'w').write(sys.version)" && python -c "import sys; open('c:\\pythonexecutable.txt', 'w').write(sys.executable)"''',
+    })
 
     # build the wheels
     subprocess.check_call([sys.executable, '-m', 'cibuildwheel', project_dir], env=env)
diff --git a/test/04_build_skip/cibuildwheel_test.py b/test/04_build_skip/cibuildwheel_test.py
index db8d4e9a..961d6e2d 100644
--- a/test/04_build_skip/cibuildwheel_test.py
+++ b/test/04_build_skip/cibuildwheel_test.py
@@ -7,8 +7,10 @@ def test():
     
     # set up the environment
     env = os.environ.copy()
-    env['CIBW_BUILD'] = 'cp3?-*'
-    env['CIBW_SKIP'] = 'cp34-*'
+    env.update({
+        'CIBW_BUILD': 'cp3?-*',
+        'CIBW_SKIP': 'cp34-*',
+    })
 
     # build the wheels
     subprocess.check_call([sys.executable, '-m', 'cibuildwheel', project_dir], env=env)
diff --git a/test/05_environment/cibuildwheel_test.py b/test/05_environment/cibuildwheel_test.py
index 7a707d91..78e43482 100644
--- a/test/05_environment/cibuildwheel_test.py
+++ b/test/05_environment/cibuildwheel_test.py
@@ -10,8 +10,10 @@ def test():
     # write some information into the CIBW_ENVIRONMENT, for expansion and
     # insertion into the environment by cibuildwheel. This is checked
     # in setup.py
-    env['CIBW_ENVIRONMENT'] = 'CIBW_TEST_VAR="a b c" CIBW_TEST_VAR_2=1 CIBW_TEST_VAR_3="$(echo \'test string 3\')" PATH=$PATH:/opt/cibw_test_path'
-    env['CIBW_ENVIRONMENT_WINDOWS'] = 'CIBW_TEST_VAR="a b c" CIBW_TEST_VAR_2=1 CIBW_TEST_VAR_3="$(echo \'test string 3\')" PATH="$PATH;/opt/cibw_test_path"'
+    env.update({
+        'CIBW_ENVIRONMENT': '''CIBW_TEST_VAR="a b c" CIBW_TEST_VAR_2=1 CIBW_TEST_VAR_3="$(echo 'test string 3')" PATH=$PATH:/opt/cibw_test_path''',
+        'CIBW_ENVIRONMENT_WINDOWS': '''CIBW_TEST_VAR="a b c" CIBW_TEST_VAR_2=1 CIBW_TEST_VAR_3="$(echo 'test string 3')" PATH="$PATH;/opt/cibw_test_path"''',
+    })
 
     # build the wheels
     subprocess.check_call([sys.executable, '-m', 'cibuildwheel', project_dir], env=env)
diff --git a/test/06_docker_images/cibuildwheel_test.py b/test/06_docker_images/cibuildwheel_test.py
index de65c0e6..7d326806 100644
--- a/test/06_docker_images/cibuildwheel_test.py
+++ b/test/06_docker_images/cibuildwheel_test.py
@@ -11,8 +11,10 @@ def test():
     env = os.environ.copy()
     # change the docker images to use. The docker image is tested in setup.py 
     # during the build
-    env['CIBW_MANYLINUX1_X86_64_IMAGE'] = 'dockcross/manylinux-x64'
-    env['CIBW_MANYLINUX1_I686_IMAGE'] = 'dockcross/manylinux-x86'
+    env.update({
+        'CIBW_MANYLINUX1_X86_64_IMAGE': 'dockcross/manylinux-x64',
+        'CIBW_MANYLINUX1_I686_IMAGE': 'dockcross/manylinux-x86',
+    })
 
     # build the wheels
     subprocess.check_call([sys.executable, '-m', 'cibuildwheel', project_dir], env=env)