diff -urp blt2.4z/src/tkButton.c blt2.4z-tk8.6/src/tkButton.c
--- blt2.4z/src/tkButton.c	2002-09-23 14:19:01.000000000 +0700
+++ blt2.4z-tk8.6/src/tkButton.c	2014-05-30 11:40:43.259449225 +0700
@@ -526,8 +526,6 @@ static int InvokeButton _ANSI_ARGS_((But
 static Blt_TileChangedProc TileChangedProc;
 static Tcl_CmdProc ButtonCmd, LabelCmd, CheckbuttonCmd, RadiobuttonCmd;
 
-EXTERN int TkCopyAndGlobalEval _ANSI_ARGS_((Tcl_Interp *interp, char *script));
-
 #if (TK_MAJOR_VERSION > 4)
 EXTERN void TkComputeAnchor _ANSI_ARGS_((Tk_Anchor anchor, Tk_Window tkwin, 
 	int padX, int padY, int innerWidth, int innerHeight, int *xPtr, 
@@ -1890,7 +1888,7 @@ InvokeButton(butPtr)
 	}
     }
     if ((butPtr->type != TYPE_LABEL) && (butPtr->command != NULL)) {
-	return TkCopyAndGlobalEval(butPtr->interp, butPtr->command);
+	return Tcl_EvalObjEx(butPtr->interp, butPtr->command, TCL_EVAL_GLOBAL);
     }
     return TCL_OK;
 }