diff --git a/js.h b/js.h
index 6e514fa..50b76f3 100644
--- a/js.h
+++ b/js.h
@@ -53,7 +53,7 @@ enum {
 enum {
 	JS_READONLY = 1,
 	JS_DONTENUM = 2,
-	JS_DONTDELETE = 4,
+	JS_DONTCONF = 4,
 };
 
 void js_newerror(js_State *J, const char *message);
diff --git a/jsbuiltin.c b/jsbuiltin.c
index cd0cb12..3a75a70 100644
--- a/jsbuiltin.c
+++ b/jsbuiltin.c
@@ -101,13 +101,13 @@ void jsB_init(js_State *J)
 
 	/* Initialize the global object */
 	js_pushnumber(J, NAN);
-	js_defglobal(J, "NaN", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+	js_defglobal(J, "NaN", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 
 	js_pushnumber(J, INFINITY);
-	js_defglobal(J, "Infinity", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+	js_defglobal(J, "Infinity", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 
 	js_pushundefined(J);
-	js_defglobal(J, "undefined", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+	js_defglobal(J, "undefined", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 
 	jsB_globalf(J, "eval", jsB_eval, 1);
 	jsB_globalf(J, "parseInt", jsB_parseInt, 1);
diff --git a/jsrun.c b/jsrun.c
index a52b5f3..76c894d 100644
--- a/jsrun.c
+++ b/jsrun.c
@@ -484,9 +484,9 @@ static void jsR_defproperty(js_State *J, js_Object *obj, const char *name,
 	ref = jsV_setproperty(J, obj, name);
 	if (value && !(ref->atts & JS_READONLY))
 		ref->value = *value;
-	if (getter && !(ref->atts & JS_DONTDELETE))
+	if (getter && !(ref->atts & JS_DONTCONF))
 		ref->getter = getter;
-	if (setter && !(ref->atts & JS_DONTDELETE))
+	if (setter && !(ref->atts & JS_DONTCONF))
 		ref->setter = setter;
 	ref->atts |= atts;
 }
@@ -510,7 +510,7 @@ static int jsR_delproperty(js_State *J, js_Object *obj, const char *name)
 
 	ref = jsV_getownproperty(J, obj, name);
 	if (ref) {
-		if (ref->atts & JS_DONTDELETE)
+		if (ref->atts & JS_DONTCONF)
 			return 0;
 		jsV_delproperty(J, obj, name);
 	}
@@ -625,7 +625,7 @@ js_Environment *jsR_newenvironment(js_State *J, js_Object *vars, js_Environment
 
 static void js_decvar(js_State *J, const char *name, int idx)
 {
-	jsR_defproperty(J, J->E->variables, name, JS_DONTENUM | JS_DONTDELETE, stackidx(J, idx), NULL, NULL);
+	jsR_defproperty(J, J->E->variables, name, JS_DONTENUM | JS_DONTCONF, stackidx(J, idx), NULL, NULL);
 }
 
 static void js_getvar(js_State *J, const char *name)
@@ -665,7 +665,7 @@ static int js_delvar(js_State *J, const char *name)
 	do {
 		js_Property *ref = jsV_getownproperty(J, E->variables, name);
 		if (ref) {
-			if (ref->atts & JS_DONTDELETE)
+			if (ref->atts & JS_DONTCONF)
 				return 0;
 			jsV_delproperty(J, E->variables, name);
 			return 1;
diff --git a/jsvalue.c b/jsvalue.c
index 033a1b6..5a9209a 100644
--- a/jsvalue.c
+++ b/jsvalue.c
@@ -194,7 +194,7 @@ static js_Object *jsV_newstring(js_State *J, const char *v)
 		ref = jsV_setproperty(J, obj, "length");
 		ref->value.type = JS_TNUMBER;
 		ref->value.u.number = utflen(v);
-		ref->atts = JS_READONLY | JS_DONTENUM | JS_DONTDELETE;
+		ref->atts = JS_READONLY | JS_DONTENUM | JS_DONTCONF;
 	}
 	return obj;
 }
@@ -246,13 +246,13 @@ void js_newfunction(js_State *J, js_Function *fun, js_Environment *scope)
 	js_pushobject(J, obj);
 	{
 		js_pushnumber(J, fun->numparams);
-		js_defproperty(J, -2, "length", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+		js_defproperty(J, -2, "length", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 		js_newobject(J);
 		{
 			js_copy(J, -2);
 			js_defproperty(J, -2, "constructor", JS_DONTENUM);
 		}
-		js_defproperty(J, -2, "prototype", JS_DONTDELETE);
+		js_defproperty(J, -2, "prototype", JS_DONTCONF);
 	}
 }
 
@@ -272,13 +272,13 @@ void js_newcfunction(js_State *J, js_CFunction cfun, int length)
 	js_pushobject(J, obj);
 	{
 		js_pushnumber(J, length);
-		js_defproperty(J, -2, "length", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+		js_defproperty(J, -2, "length", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 		js_newobject(J);
 		{
 			js_copy(J, -2);
 			js_defproperty(J, -2, "constructor", JS_DONTENUM);
 		}
-		js_defproperty(J, -2, "prototype", JS_DONTDELETE);
+		js_defproperty(J, -2, "prototype", JS_DONTCONF);
 	}
 }
 
@@ -291,11 +291,11 @@ void js_newcconstructor(js_State *J, js_CFunction cfun, js_CFunction ccon, int l
 	js_pushobject(J, obj); /* proto obj */
 	{
 		js_pushnumber(J, length);
-		js_defproperty(J, -2, "length", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+		js_defproperty(J, -2, "length", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 		js_rot2(J); /* obj proto */
 		js_copy(J, -2); /* obj proto obj */
 		js_defproperty(J, -2, "constructor", JS_DONTENUM);
-		js_defproperty(J, -2, "prototype", JS_READONLY | JS_DONTENUM | JS_DONTDELETE);
+		js_defproperty(J, -2, "prototype", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
 	}
 }