diff --git a/requirements/default.txt b/requirements/default.txt
index 0de34571e..7fa2d2c5f 100644
--- a/requirements/default.txt
+++ b/requirements/default.txt
@@ -10,7 +10,8 @@ nanotime>=0.5.2
 pyasn1>=0.4.1
 voluptuous>=0.11.7
 requests>=2.22.0
-grandalf>=0.6
+# See https://github.com/bdcht/grandalf/issues/26
+grandalf==0.6
 distro>=1.3.0
 appdirs>=1.4.3
 ruamel.yaml>=0.17.11
@@ -42,4 +43,4 @@ pyparsing==2.4.7
 typing_extensions>=3.10.0.2
 fsspec[http]>=2021.8.1
 aiohttp-retry==2.4.5
-diskcache>=5.2.1
\ No newline at end of file
+diskcache>=5.2.1