diff --git a/tools/cli/option-from-string.go b/tools/cli/option-from-string.go
index 0172a69d2..608b5b8ca 100644
--- a/tools/cli/option-from-string.go
+++ b/tools/cli/option-from-string.go
@@ -45,6 +45,13 @@ func OptionFromString(entries ...string) (*Option, error) {
 	return option_from_string(map[string]string{}, entries...)
 }
 
+func is_string_slice(f reflect.Value) bool {
+	if f.Kind() != reflect.Slice {
+		return false
+	}
+	return f.Type().Elem().Kind() == reflect.String
+}
+
 func OptionsFromStruct(pointer_to_options_struct interface{}) ([]*Option, error) {
 	val := reflect.ValueOf(pointer_to_options_struct).Elem()
 	if val.Kind() != reflect.Struct {
@@ -61,6 +68,9 @@ func OptionsFromStruct(pointer_to_options_struct interface{}) ([]*Option, error)
 		typ := "str"
 		switch f.Kind() {
 		case reflect.Slice:
+			if !is_string_slice(f) {
+				return nil, fmt.Errorf("The field %s is not a slice of strings", field_name)
+			}
 			typ = "list"
 		case reflect.Int:
 			typ = "int"
diff --git a/tools/cli/types.go b/tools/cli/types.go
index 2bef4c6f6..7235a10c4 100644
--- a/tools/cli/types.go
+++ b/tools/cli/types.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"os"
 	"reflect"
-	"regexp"
 	"strconv"
 	"strings"
 
@@ -425,8 +424,8 @@ func (self *Command) GetOptionValues(pointer_to_options_struct interface{}) erro
 			f.SetBool(v)
 		case StringOption:
 			if opt.IsList {
-				if f.Kind() != reflect.Slice {
-					return fmt.Errorf("The field: %s must be a slice", field_name)
+				if !is_string_slice(f) {
+					return fmt.Errorf("The field: %s must be a []string", field_name)
 				}
 				v := opt.parsed_value().([]string)
 				f.Set(reflect.ValueOf(v))