diff --git a/plugins/python/pyhelpers.c b/plugins/python/pyhelpers.c
index 6b235f3df..8fbf0f80a 100644
--- a/plugins/python/pyhelpers.c
+++ b/plugins/python/pyhelpers.c
@@ -212,7 +212,7 @@ py_str_array_from_tuple(PyObject *py_tuple)
     Py_ssize_t tuple_size = PyTuple_Size(py_tuple);
 
     // we need an extra 0 at the end
-    char **result = calloc(Py_SSIZE2SIZE(tuple_size) + 1, sizeof(char*));
+    char **result = calloc(tuple_size + 1, sizeof(char *));
     if (result == NULL) {
         debug_return_ptr(NULL);
     }
diff --git a/plugins/python/pyhelpers.h b/plugins/python/pyhelpers.h
index 01843d7dc..524b14e3b 100644
--- a/plugins/python/pyhelpers.h
+++ b/plugins/python/pyhelpers.h
@@ -52,7 +52,6 @@ struct PythonContext
 extern struct PythonContext py_ctx;
 
 #define Py_TYPENAME(object) (object ? Py_TYPE(object)->tp_name : "NULL")
-#define Py_SSIZE2SIZE(value) ((value) < 0 ? 0 : (size_t)(value))
 
 #define py_sudo_log(...) py_ctx.sudo_log(__VA_ARGS__)
 
diff --git a/plugins/python/python_convmessage.c b/plugins/python/python_convmessage.c
index 67e6d96bc..14283dcd7 100644
--- a/plugins/python/python_convmessage.c
+++ b/plugins/python/python_convmessage.c
@@ -137,7 +137,7 @@ sudo_module_ConvMessages_to_c(PyObject *py_tuple, Py_ssize_t *num_msgs, struct s
         debug_return_int(SUDO_RC_ERROR);
     }
 
-    *msgs = calloc(Py_SSIZE2SIZE(*num_msgs), sizeof(struct sudo_conv_message));
+    *msgs = calloc(*num_msgs, sizeof(struct sudo_conv_message));
     if (*msgs == NULL) {
         debug_return_int(SUDO_RC_ERROR);
     }
diff --git a/plugins/python/sudo_python_module.c b/plugins/python/sudo_python_module.c
index bd189df9a..897d471fc 100644
--- a/plugins/python/sudo_python_module.c
+++ b/plugins/python/sudo_python_module.c
@@ -346,11 +346,12 @@ python_sudo_conversation(PyObject *Py_UNUSED(self), PyObject *py_args, PyObject
         goto cleanup;
     }
 
+    /* sudo_module_ConvMessages_to_c() returns error if no messages. */
     if (sudo_module_ConvMessages_to_c(py_args, &num_msgs, &msgs) < 0) {
         goto cleanup;
     }
 
-    replies = calloc(Py_SSIZE2SIZE(num_msgs), sizeof(struct sudo_conv_reply));
+    replies = calloc(num_msgs, sizeof(struct sudo_conv_reply));
     if (replies == NULL)
         goto cleanup;
     py_result = PyTuple_New(num_msgs);