diff --git a/src/afd.c b/src/afd.c
index a2f9d24..425ec1c 100644
--- a/src/afd.c
+++ b/src/afd.c
@@ -116,7 +116,7 @@ static ssize_t _afd_get_protocol_info(SOCKET socket,
                  SO_PROTOCOL_INFOW,
                  (char*) protocol_info,
                  &opt_len) != 0)
-    return_handle_error(-1, socket);
+    return_error(-1);
 
   id = -1;
   for (size_t i = 0; i < array_count(AFD_PROVIDER_GUID_LIST); i++) {
diff --git a/src/api.c b/src/api.c
index 10438de..25e8d20 100644
--- a/src/api.c
+++ b/src/api.c
@@ -79,22 +79,34 @@ int epoll_close(HANDLE ephnd) {
 int epoll_ctl(HANDLE ephnd, int op, SOCKET sock, struct epoll_event* ev) {
   reflock_tree_node_t* tree_node;
   ep_port_t* port_info;
-  int result;
+  int r;
 
   if (init() < 0)
     return -1;
 
   tree_node =
       reflock_tree_find_and_ref(&_epoll_handle_tree, (uintptr_t) ephnd);
-  if (tree_node == NULL)
-    return_handle_error(-1, ephnd, ERROR_INVALID_PARAMETER);
-  port_info = _handle_tree_node_to_port(tree_node);
+  if (tree_node == NULL) {
+    err_set_win_error(ERROR_INVALID_PARAMETER);
+    goto err;
+  }
 
-  result = ep_port_ctl(port_info, op, sock, ev);
+  port_info = _handle_tree_node_to_port(tree_node);
+  r = ep_port_ctl(port_info, op, sock, ev);
 
   reflock_tree_node_unref(tree_node);
 
-  return result;
+  if (r < 0)
+    goto err;
+
+  return 0;
+
+err:
+  /* On Linux, in the case of epoll_ctl_mod(), EBADF takes precendence over
+   * other errors. Wepoll copies this behavior. */
+  err_check_handle(ephnd);
+  err_check_handle((HANDLE) sock);
+  return -1;
 }
 
 int epoll_wait(HANDLE ephnd,
diff --git a/src/port.c b/src/port.c
index f0631b7..4505321 100644
--- a/src/port.c
+++ b/src/port.c
@@ -320,7 +320,7 @@ static int _ep_port_ctl_op(ep_port_t* port_info,
     case EPOLL_CTL_DEL:
       return _ep_port_ctl_del(port_info, sock);
     default:
-      return_handle_error(-1, sock, ERROR_INVALID_PARAMETER);
+      return_error(-1, ERROR_INVALID_PARAMETER);
   }
 }
 
@@ -355,7 +355,7 @@ ep_sock_t* ep_port_find_socket(ep_port_t* port_info, SOCKET socket) {
   ep_sock_t* sock_info = safe_container_of(
       tree_find(&port_info->sock_tree, socket), ep_sock_t, tree_node);
   if (sock_info == NULL)
-    return_handle_error(NULL, socket, ERROR_NOT_FOUND);
+    return_error(NULL, ERROR_NOT_FOUND);
   return sock_info;
 }
 
diff --git a/test/test-error.c b/test/test-error.c
index b15cff9..f2f95c9 100644
--- a/test/test-error.c
+++ b/test/test-error.c
@@ -101,7 +101,8 @@ int main(void) {
     check_error(r < 0, EBADF, ERROR_INVALID_HANDLE);
     r = epoll_ctl(valid_ephnd, -1, INVALID_SOCKET, &ev);
     check_error(r < 0, EBADF, ERROR_INVALID_HANDLE);
-    /* TODO: bad `ephnd` type with invalid `sock`. */
+    r = epoll_ctl(bad_type, -1, INVALID_SOCKET, &ev);
+    check_error(r < 0, EBADF, ERROR_INVALID_HANDLE);
 
     r = closesocket(sock_valid);
     check(r == 0);