diff --git a/tox.ini b/tox.ini
index 5cbfdd5e1a..589d07b8cb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -79,7 +79,7 @@ commands = pytest \
 [testenv:khmer_master]
 basepython = python3.8
 deps =
-  -e git+https://github.com/dib-lab/khmer.git#egg=khmer
+  -e git+https://github.com/dib-lab/khmer.git\#egg=khmer
 commands = pytest \
            --cov "{envsitepackagesdir}/sourmash" \
            --cov-config "{toxinidir}/tox.ini" \