Index: main/panel.lisp
===================================================================
--- main/panel.lisp	(revision main,33)
+++ main/panel.lisp	(revision main,41)
@@ -56,5 +56,5 @@
   (let ((panel-ptr (new-panel (window-pointer window))))
     (when (null-pointer-p panel-ptr)
-      (signal 'panel-construction-error))
+      (error 'panel-construction-error))
     (make-instance 'panel :panel-ptr panel-ptr :client-window window)))
 
@@ -73,5 +73,5 @@
   (with-slots (panel-ptr) panel
     (unless (= (del-panel panel-ptr) +ok+)
-      (signal 'panel-destruction-error))))
+      (error 'panel-destruction-error))))
 
 
Index: main/window/screen.lisp
===================================================================
--- main/window/screen.lisp	(revision main,29)
+++ main/window/screen.lisp	(revision main,41)
@@ -31,5 +31,5 @@
     `(let ((,ptr (initscr)))
        (when (null-pointer-p ,ptr)
-         (signal 'screen-initialization-error))
+         (error 'screen-initialization-error))
        (unwind-protect
             (start-color)
@@ -64,5 +64,5 @@
   (let ((ptr (derwin (window-pointer w) height width y x)))
     (when (null-pointer-p ptr)
-      (signal 'screen-window-creation-error))
+      (error 'screen-window-creation-error))
     (make-instance 'screen-window :ptr ptr)))
 
@@ -70,5 +70,5 @@
   (with-slots (ptr) w
     (when (= (delwin ptr) +err+)
-      (signal 'screen-window-destruction-error)))
+      (error 'screen-window-destruction-error)))
   (values))
 
@@ -79,5 +79,5 @@
     `(let ((,ptr (newwin ,height ,width ,y ,x)))
        (when (null-pointer-p ,ptr)
-         (signal 'screen-window-creation-error))
+         (error 'screen-window-creation-error))
        (let ((,window (make-instance 'screen-window :ptr ,ptr)))
          (unwind-protect (progn ,@body)