diff --git a/src/frontend/plotting/x11.c b/src/frontend/plotting/x11.c
index af277922e..c03d96e0c 100644
--- a/src/frontend/plotting/x11.c
+++ b/src/frontend/plotting/x11.c
@@ -314,7 +314,7 @@ handlebuttonev(Widget w, caddr_t clientdata, caddr_t calldata)
 
 
 /* Recover from bad NewViewPort call. */
-#define RECOVERNEWVIEWPORT()    tfree((char *) graph);\
+#define RECOVERNEWVIEWPORT()    tfree(graph);\
 	            graph = (GRAPH *) NULL; 
 	    /* need to do this or else DestroyGraph will free it again */