diff --git a/conf.py b/conf.py
index e14c6ace83..dd2de7b899 100644
--- a/conf.py
+++ b/conf.py
@@ -265,19 +265,9 @@ rst_epilog = """
 
 # -- Options for HTML output ----------------------------------------------
 
-# on_rtd is whether we are on readthedocs.org
-on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
-
-if not on_rtd:  # only import and set the theme if we're building docs locally
-    try:
-        import sphinx_rtd_theme
-        html_theme = 'sphinx_rtd_theme'
-        html_theme_path = [sphinx_rtd_theme.get_html_theme_path(), '.']
-    except:
-        html_theme = 'default'
-        html_theme_path = ['.']
-else:
-    html_theme_path = ['.']
+import sphinx_rtd_theme
+html_theme = 'sphinx_rtd_theme'
+html_theme_path = [sphinx_rtd_theme.get_html_theme_path(), '.']
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the