diff --git a/contrib/x11/examples/lesson2.factor b/contrib/x11/examples/lesson2.factor
index 6b070cab38..e81d72c55e 100644
--- a/contrib/x11/examples/lesson2.factor
+++ b/contrib/x11/examples/lesson2.factor
@@ -58,7 +58,7 @@ SYMBOL: height
     CWBorderPixel CWColormap bitor CWEventMask bitor swap ;
 
 : make-display ( display-num -- display )
-    XOpenDisplay dup dpy set ;
+    dup [ <c-string> ] when XOpenDisplay dup dpy set ;
 
 : make-screen ( display -- screen )
     XDefaultScreen dup screen set ;
diff --git a/contrib/x11/x.factor b/contrib/x11/x.factor
index 66a18124c6..23b04d5a75 100644
--- a/contrib/x11/x.factor
+++ b/contrib/x11/x.factor
@@ -1,5 +1,4 @@
-USING: namespaces kernel words compiler math arrays strings alien sequences io
-prettyprint x11 rectangle ;
+USING: alien namespaces kernel words compiler math arrays strings alien sequences io prettyprint x11 rectangle ;
 
 IN: x 
 
@@ -500,7 +499,7 @@ nip ;
 [ swap gcontext set call ] with-scope ; inline
 
 : initialize-x ( display-string -- )
-  XOpenDisplay dpy set
+  dup [ string>char-alien ] when XOpenDisplay dpy set
   dpy get XDefaultScreen scr set
   dpy get scr get XRootWindow root set
   dpy get scr get XBlackPixel black-pixel set
@@ -589,7 +588,7 @@ dpy get win get "XWindowAttributes" <c-object> XGetWindowAttributes 0 = not ;
 swap >array [ swap char-nth ] map-with >string ;
 
 : lookup-string ( event -- string )
-10 "char" <c-array> dup >r 10 0 <alien> 0 <alien> XLookupString r>
+10 "char" <c-array> dup >r 10 f f XLookupString r>
 char-array>string ;
 
 : send-client-message ( atom x -- )
diff --git a/library/compiler/alien/alien-invoke.factor b/library/compiler/alien/alien-invoke.factor
index 65775a87e3..35e284ac19 100644
--- a/library/compiler/alien/alien-invoke.factor
+++ b/library/compiler/alien/alien-invoke.factor
@@ -19,9 +19,6 @@ C: alien-invoke make-node ;
 
 TUPLE: alien-invoke-error library symbol ;
 
-M: alien-invoke-error summary ( error -- )
-    drop "Words calling ``alien-invoke'' cannot run in the interpreter. Compile the caller word and try again." ;
-
 : alien-invoke ( ... return library function parameters -- ... )
     pick pick <alien-invoke-error> throw ;
 
diff --git a/library/ui/x11/utilities.factor b/library/ui/x11/utilities.factor
index e952566691..30e5033608 100644
--- a/library/ui/x11/utilities.factor
+++ b/library/ui/x11/utilities.factor
@@ -22,6 +22,7 @@ SYMBOL: root
     [ "Cannot connect to X server - check $DISPLAY" throw ] unless* ;
 
 : initialize-x ( display-string -- )
+    dup [ string>char-alien ] when
     XOpenDisplay check-display dpy set-global
     dpy get XDefaultScreen scr set-global
     dpy get scr get XRootWindow root set-global ;
diff --git a/library/ui/x11/xlib.factor b/library/ui/x11/xlib.factor
index 9bc1d0acf0..050da43189 100644
--- a/library/ui/x11/xlib.factor
+++ b/library/ui/x11/xlib.factor
@@ -62,7 +62,7 @@ TYPEDEF: void* Atom**
 ! 2 - Display Functions
 !
 
-FUNCTION: Display* XOpenDisplay ( char* display_name ) ;
+FUNCTION: Display* XOpenDisplay ( void* display_name ) ;
 
 ! 2.2 Obtaining Information about the Display, Image Formats, or Screens
 
@@ -1175,7 +1175,7 @@ FUNCTION: KeySym XLookupKeysym ( XKeyEvent* key_event, int index ) ;
 
 FUNCTION: int XLookupString (
 	XKeyEvent* event_struct,
-	char* buffer_return,
+	void* buffer_return,
 	int bytes_buffer,
 	KeySym* keysym_return,
 	XComposeStatus* status_in_out ) ;