diff --git a/Makefile.inc1 b/Makefile.inc1
index e44182f40a2..746cea546ef 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -460,7 +460,8 @@ BFLAGS+=	-B${CROSS_BINUTILS_PREFIX}
 .endif
 
 # External compiler needs sysroot and target flags.
-.if ${MK_CROSS_COMPILER} == "no"
+.if ${MK_CROSS_COMPILER} == "no" || \
+    (${MK_CLANG_BOOTSTRAP} == "no" && ${MK_GCC_BOOTSTRAP} == "no")
 .if !defined(CROSS_BINUTILS_PREFIX) || !exists(${CROSS_BINUTILS_PREFIX})
 BFLAGS+=	-B${WORLDTMP}/usr/bin
 .endif