diff --git a/.travis.yml b/.travis.yml
index ba33567..b0d6378 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,15 +3,14 @@ fast_finish: true
 
 python:
   - 3.5
-  - 3.7-dev
+  - 3.6
 
 os:
   - linux
 
+sudo: required
 dist: trusty
 group: edge
-  
-env: FC=gfortran-6
 
 notifications:
   email: false
@@ -26,11 +25,12 @@ addons:
     packages: gfortran-6
 
 before_install:
-    - pip -q install coveralls
-    # temp for pip < 9.1
-    - pip -q install numpy
+  - sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-6 50
+  - pip -q install coveralls
+  # temp for pip < 9.1
+  - pip -q install numpy
 
-install: pip  install -e .
+install: pip install -e .
 
 script: 
   - coverage run tests/test.py -v
diff --git a/setup.py b/setup.py
index f622979..fad6cb5 100755
--- a/setup.py
+++ b/setup.py
@@ -4,6 +4,10 @@
 from setuptools import find_packages
 from numpy.distutils.core import setup,Extension
 
+ext = [Extension(name='lowtran7',
+                 sources=['lowtran7.f'],
+                 f2py_options=['--quiet'])]
+
 setup(name='lowtran',
       packages=find_packages(),
       author='Michael Hirsch, Ph.D',
@@ -18,8 +22,7 @@
       'Programming Language :: Python',
       'Programming Language :: Python :: 3',
       ],
-      ext_modules=[Extension(name='lowtran7',sources=['lowtran7.f'],
-                    f2py_options=['--quiet'])],
+      ext_modules=ext,
       install_requires=req,
       python_requires='>=3.5',
       extras_require={'plot':['matplotlib','seaborn']},