diff --git a/src/pkg/runtime/noasm_arm.goc b/src/pkg/runtime/noasm.goc
similarity index 97%
rename from src/pkg/runtime/noasm_arm.goc
rename to src/pkg/runtime/noasm.goc
index fe3591e8a37..4966677293c 100644
--- a/src/pkg/runtime/noasm_arm.goc
+++ b/src/pkg/runtime/noasm.goc
@@ -5,6 +5,8 @@
 // Routines that are implemented in assembly in asm_{amd64,386}.s
 // but are implemented in C for arm.
 
+// +build arm power64 power64le
+
 package runtime
 #include "runtime.h"
 #include "../../cmd/ld/textflag.h"