diff --git a/config/toolchain.in b/config/toolchain.in
--- a/config/toolchain.in
+++ b/config/toolchain.in
@@ -20,7 +20,7 @@
 
 config SYSROOT_NAME
     string
-    prompt "sysroot directory name"
+    prompt "sysroot directory name" if ! BACKEND
     depends on USE_SYSROOT
     default "sysroot"
     help