diff --git a/boundaries/createindexlist.py b/boundaries/createindexlist.py
index 4eecddc474907e97a3ca6193beb925ec1ffda8d6..49863c815b55d7a86f630deb3426de3ab6b583a2 100644
--- a/boundaries/createindexlist.py
+++ b/boundaries/createindexlist.py
@@ -5,7 +5,7 @@ import warnings
 try:
     import pyximport
 
-    pyximport.install()
+    pyximport.install(language_level=3)
     from pystencils.boundaries.createindexlistcython import create_boundary_index_list_2d, create_boundary_index_list_3d
 
     cython_funcs_available = True
diff --git a/cpu/msvc_detection.py b/cpu/msvc_detection.py
index 7c45d484f97a5569305caf937e41be3e15dda1d5..be0fb9189ae3d4516472ec1f76da6b15284847a3 100644
--- a/cpu/msvc_detection.py
+++ b/cpu/msvc_detection.py
@@ -35,7 +35,7 @@ def get_environment(version_specifier, arch='x64'):
 def find_latest_msvc_version_using_environment_variables():
     import re
     # noinspection SpellCheckingInspection
-    regex = re.compile('VS(\d\d)\dCOMNTOOLS')
+    regex = re.compile(r'VS(\d\d)\dCOMNTOOLS')
     versions = []
     for key, value in os.environ.items():
         match = regex.match(key)