diff --git a/mitmproxy/command.py b/mitmproxy/command.py
index 8822bb9b8..bfec47e11 100644
--- a/mitmproxy/command.py
+++ b/mitmproxy/command.py
@@ -284,7 +284,7 @@ def parsearg(manager: CommandManager, spec: str, argtype: type) -> typing.Any:
     try:
         return t.parse(manager, argtype, spec)
     except exceptions.TypeError as e:
-        raise exceptions.CommandError from e
+        raise exceptions.CommandError(str(e)) from e
 
 
 def command(name: typing.Optional[str] = None):
diff --git a/mitmproxy/types.py b/mitmproxy/types.py
index ac9922172..0d4ffd696 100644
--- a/mitmproxy/types.py
+++ b/mitmproxy/types.py
@@ -134,7 +134,7 @@ class _IntType(_BaseType):
         try:
             return int(s)
         except ValueError as e:
-            raise exceptions.TypeError from e
+            raise exceptions.TypeError(str(e)) from e
 
     def is_valid(self, manager: "CommandManager", typ: typing.Any, val: typing.Any) -> bool:
         return isinstance(val, int)
@@ -328,7 +328,7 @@ class _FlowType(_BaseFlowType):
         try:
             flows = manager.execute("view.flows.resolve %s" % (s))
         except exceptions.CommandError as e:
-            raise exceptions.TypeError from e
+            raise exceptions.TypeError(str(e)) from e
         if len(flows) != 1:
             raise exceptions.TypeError(
                 "Command requires one flow, specification matched %s." % len(flows)
@@ -347,7 +347,7 @@ class _FlowsType(_BaseFlowType):
         try:
             return manager.execute("view.flows.resolve %s" % (s))
         except exceptions.CommandError as e:
-            raise exceptions.TypeError from e
+            raise exceptions.TypeError(str(e)) from e
 
     def is_valid(self, manager: "CommandManager", typ: typing.Any, val: typing.Any) -> bool:
         try: