diff --git a/docs/conf.py b/docs/conf.py
index 4ec5a8a..bfdfb8c 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -297,6 +297,6 @@
 
 # Example configuration for intersphinx: refer to the Python standard library.
 intersphinx_mapping = {'python': ('http://docs.python.org/3', None)}
-latex_preamble = """
+latex_preamble = r"""
 \usepackage{upquote}
 """