diff --git a/arm64/mkfile b/arm64/mkfile
new file mode 100644
index 000000000..2643f5df1
--- /dev/null
+++ b/arm64/mkfile
@@ -0,0 +1,6 @@
+</sys/src/mkfile.proto
+
+CC=7c
+LD=7l
+AS=7a
+O=7
diff --git a/sys/src/mkfile.proto b/sys/src/mkfile.proto
index ba0b4ed63..1947735c9 100644
--- a/sys/src/mkfile.proto
+++ b/sys/src/mkfile.proto
@@ -2,7 +2,7 @@
 # common mkfile parameters shared by all architectures
 #
 
-OS=0568qv
+OS=05678qv
 CPUS=spim arm amd64 386 power mips
 CFLAGS=-FTVw
 LEX=lex