diff --git a/internal/mkcgo/generate.go b/internal/mkcgo/generate.go
index 3030d813..2c79ba38 100644
--- a/internal/mkcgo/generate.go
+++ b/internal/mkcgo/generate.go
@@ -275,7 +275,6 @@ func (r *rets) useLongHandleErrorCode(retvar, msg string) string {
 	if strings.HasSuffix(r.typ, "*") || strings.HasSuffix(strings.ToUpper(r.typ), "_PTR") {
 		cond = retvar + " == nil"
 	} else {
-		cond = retvar + " != " + defaultErrorCodeStr
 		cond = strings.Replace(r.failCond, "retval", retvar, 1)
 	}
 	return fmt.Sprintf(code, cond, msg)
diff --git a/internal/mkcgo/mkcgo.go b/internal/mkcgo/mkcgo.go
index 8d91cbd2..403846f8 100644
--- a/internal/mkcgo/mkcgo.go
+++ b/internal/mkcgo/mkcgo.go
@@ -10,10 +10,6 @@ import (
 	"strings"
 )
 
-var (
-	defaultErrorCodeStr string
-)
-
 var (
 	fileName      = flag.String("out", "", "output file name (standard output if omitted)")
 	includeHeader = flag.String("include", "", "include header file")