diff --git a/.travis.yml b/.travis.yml
index 06fcb888f9..df11c1e3c7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -47,7 +47,7 @@ before_script:
   - export OPENMC_CROSS_SECTIONS=$PWD/nndc/cross_sections.xml
   - wget http://web.mit.edu/smharper/Public/multipole_lib.tar.gz
   - tar -xzf multipole_lib.tar.gz
-  - export MULTIPOLE_LIBRARY=$PWD/multipole_lib
+  - export OPENMC_MULTIPOLE_LIBRARY=$PWD/multipole_lib
   - cd ..
 
 script:
diff --git a/docs/source/usersguide/input.rst b/docs/source/usersguide/input.rst
index d3d050cb27..ace77a3954 100644
--- a/docs/source/usersguide/input.rst
+++ b/docs/source/usersguide/input.rst
@@ -288,7 +288,7 @@ The ``<multipole_library>`` element indicates the directory containing a
 windowed multipole library. If a windowed multipole library is available,
 OpenMC can use it for on-the-fly Doppler-broadening of resolved resonance range
 cross sections. If this element is absent from the settings.xml file, the
-:envvar:`MULTIPOLE_LIBRARY` environment variable will be used.
+:envvar:`OPENMC_MULTIPOLE_LIBRARY` environment variable will be used.
 
   .. note:: The <use_windowed_multipole> element must also be set to "True"
     for windowed multipole functionality.
diff --git a/openmc/settings.py b/openmc/settings.py
index be1fdb36c8..566230fb99 100644
--- a/openmc/settings.py
+++ b/openmc/settings.py
@@ -76,8 +76,9 @@ class SettingsFile(object):
         calculations to find the path to the XML cross section file.
     multipole_library : str
         Indicates the path to a directory containing a windowed multipole
-        cross section library. If it is not set, the :envvar:`MULTIPOLE_LIBRARY'
-        environment variable will be used. A multipole library is optional.
+        cross section library. If it is not set, the
+        :envvar:`OPENMC_MULTIPOLE_LIBRARY' environment variable will be used. A
+        multipole library is optional.
     energy_grid : {'nuclide', 'logarithm', 'material-union'}
         Set the method used to search energy grids.
     energy_mode : {'continuous-energy', 'multi-group'}
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index f58009f866..1f5b0d3e84 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -136,9 +136,9 @@ contains
               call fatal_error("No cross_sections.xml file was specified in &
                    &settings.xml or in the OPENMC_CROSS_SECTIONS environment &
                    &variable. OpenMC needs such a file to identify where to &
-                   &find ACE cross section libraries. Please consult the user's &
-                   &guide at http://mit-crpg.github.io/openmc for information on &
-                   &how to set up ACE cross section libraries.")
+                   &find ACE cross section libraries. Please consult the &
+                   &user's guide at http://mit-crpg.github.io/openmc for &
+                   &information on how to set up ACE cross section libraries.")
             else
               call warning("The CROSS_SECTIONS environment variable is &
                    &deprecated. Please update your environment to use &
@@ -147,7 +147,8 @@ contains
           end if
           path_cross_sections = trim(env_variable)
         else
-          call get_environment_variable("OPENMC_MG_CROSS_SECTIONS", env_variable)
+          call get_environment_variable("OPENMC_MG_CROSS_SECTIONS", &
+                                        env_variable)
           if (len_trim(env_variable) == 0) then
             call fatal_error("No cross_sections.xml file was specified in &
                  &settings.xml or in the OPENMC_MG_CROSS_SECTIONS environment &
@@ -170,7 +171,7 @@ contains
            run_mode /= MODE_PLOTTING) then
         ! No library location specified in settings.xml, check
         ! environment variable
-        call get_environment_variable("MULTIPOLE_LIBRARY", env_variable)
+        call get_environment_variable("OPENMC_MULTIPOLE_LIBRARY", env_variable)
         path_multipole = trim(env_variable)
       else
         call get_node_value(doc, "multipole_library", path_multipole)