diff --git a/sandbox/grist/functions/date.py b/sandbox/grist/functions/date.py
index c38651d7..5a24340a 100644
--- a/sandbox/grist/functions/date.py
+++ b/sandbox/grist/functions/date.py
@@ -292,7 +292,7 @@ def DATEVALUE(date_string, tz=None):
   >>> DATEVALUE("asdf")
   Traceback (most recent call last):
   ...
-  ValueError: Unknown string format
+  dateutil.parser._parser.ParserError: Unknown string format: asdf
   """
   return dateutil.parser.parse(date_string).replace(tzinfo=_get_tzinfo(tz))
 
diff --git a/sandbox/requirements3.txt b/sandbox/requirements3.txt
index 38fb0a18..f0e39250 100644
--- a/sandbox/requirements3.txt
+++ b/sandbox/requirements3.txt
@@ -13,7 +13,7 @@ backports.functools-lru-cache==1.6.4
 chardet==4.0.0
 enum34==1.1.10
 et-xmlfile==1.0.1
-html5lib==0.999999999
+html5lib==1.1
 iso8601==0.1.12
 jdcal==1.4.1
 json_table_schema==0.2.1
@@ -21,12 +21,12 @@ lazy_object_proxy==1.6.0
 lxml==4.6.3                # used in csv plugin only?
 messytables==0.15.2
 openpyxl==2.6.4
-python_dateutil==2.6.0
+python_dateutil==2.8.2
 python_magic==0.4.12
 roman==2.0.0
 singledispatch==3.6.2
 six==1.16.0
-sortedcontainers==1.5.7
+sortedcontainers==2.4.0
 webencodings==0.5
 wrapt==1.12.1
 xlrd==1.2.0