diff --git a/generic/tclIOSock.c b/generic/tclIOSock.c
index 4b2c637fe42..47fde3672cf 100644
--- a/generic/tclIOSock.c
+++ b/generic/tclIOSock.c
@@ -75,7 +75,7 @@ TclSockGetPort(
 	 * Don't bother translating 'proto' to native.
 	 */
 
-	if (Tcl_UtfToExternalDStringEx(interp, TCLFSENCODING, string, -1, 0, &ds, NULL) != TCL_OK) {
+	if (Tcl_UtfToExternalDStringEx(interp, NULL, string, -1, 0, &ds, NULL) != TCL_OK) {
 	    Tcl_DStringFree(&ds);
 	    return TCL_ERROR;
 	}
@@ -188,7 +188,7 @@ TclCreateSocketAddress(
     int result;
 
     if (host != NULL) {
-	if (Tcl_UtfToExternalDStringEx(interp, TCLFSENCODING, host, -1, 0, &ds, NULL) != TCL_OK) {
+	if (Tcl_UtfToExternalDStringEx(interp, NULL, host, -1, 0, &ds, NULL) != TCL_OK) {
 		Tcl_DStringFree(&ds);
 	    return 0;
 	}
diff --git a/win/tclWinPipe.c b/win/tclWinPipe.c
index fd183cfda38..9f889b284d2 100644
--- a/win/tclWinPipe.c
+++ b/win/tclWinPipe.c
@@ -679,7 +679,7 @@ TclpCreateTempFile(
 	 * Convert the contents from UTF to native encoding
 	 */
 
-	if (Tcl_UtfToExternalDStringEx(NULL, TCLFSENCODING, contents, TCL_INDEX_NONE, 0, &dstring, NULL) != TCL_OK) {
+	if (Tcl_UtfToExternalDStringEx(NULL, NULL, contents, TCL_INDEX_NONE, 0, &dstring, NULL) != TCL_OK) {
 	   goto error;
 	}
 	native = Tcl_DStringValue(&dstring);