diff --git a/easyargs/parsers.py b/easyargs/parsers.py
index 8c9adea..9ab9dd7 100644
--- a/easyargs/parsers.py
+++ b/easyargs/parsers.py
@@ -106,7 +106,12 @@ def function_parser(function, parser):
     main_text, params_help = parser_help_text(help_text)
 
     # Get the function information
-    args, varargs, keywords, defaults = inspect.getargspec(function)
+    full_arg_spec = inspect.getfullargspec(function)
+    args = full_arg_spec.args
+    varargs = full_arg_spec.varargs
+    keywords = full_arg_spec.kwonlydefaults
+    defaults = full_arg_spec.defaults
+
     if args is None:
         args = []
 
diff --git a/tox.ini b/tox.ini
index f2f8cb6..3543ed9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py26, py27, py33, py34, py35
+envlist = py26, py27, py33, py34, py35, py312
 
 [testenv]
 commands =