diff --git a/src/cmd/compile/internal/ssa/_gen/rulegen.go b/src/cmd/compile/internal/ssa/_gen/rulegen.go
index 072df298f37..d6f3852b430 100644
--- a/src/cmd/compile/internal/ssa/_gen/rulegen.go
+++ b/src/cmd/compile/internal/ssa/_gen/rulegen.go
@@ -102,7 +102,7 @@ func genRulesSuffix(arch arch, suff string) {
 		// Some architectures have bonus rules files that others don't share. That's fine.
 		return
 	}
-
+	defer text.Close()
 	// oprules contains a list of rules for each block and opcode
 	blockrules := map[string][]Rule{}
 	oprules := map[string][]Rule{}