Fix multiple flag options completion
diff --git a/completion.go b/completion.go
index 708fa9e..6a0432b 100644
--- a/completion.go
+++ b/completion.go
@@ -120,6 +120,9 @@
 }
 
 func (c *completion) completeValue(value reflect.Value, prefix string, match string) []Completion {
+	if value.Kind() == reflect.Slice {
+		value = reflect.New(value.Type().Elem())
+	}
 	i := value.Interface()
 
 	var ret []Completion
@@ -139,16 +142,6 @@
 	return ret
 }
 
-func (c *completion) completeArg(arg *Arg, prefix string, match string) []Completion {
-	if arg.isRemaining() {
-		// For remaining positional args (that are parsed into a slice), complete
-		// based on the element type.
-		return c.completeValue(reflect.New(arg.value.Type().Elem()), prefix, match)
-	}
-
-	return c.completeValue(arg.value, prefix, match)
-}
-
 func (c *completion) complete(args []string) []Completion {
 	if len(args) == 0 {
 		args = []string{""}
@@ -263,7 +256,7 @@
 		}
 	} else if len(s.positional) > 0 {
 		// Complete for positional argument
-		ret = c.completeArg(s.positional[0], "", lastarg)
+		ret = c.completeValue(s.positional[0].value, "", lastarg)
 	} else if len(s.command.commands) > 0 {
 		// Complete for command
 		ret = c.completeCommands(s, lastarg)
diff --git a/completion_test.go b/completion_test.go
index 72ee158..af81993 100644
--- a/completion_test.go
+++ b/completion_test.go
@@ -52,8 +52,13 @@
 		Positional struct {
 			Filename []Filename
 		} `positional-args:"yes"`
+		Extra []Filename `short:"f"`
 	} `command:"add-multi" description:"add multiple items"`
 
+	AddMultiCommandFlag struct {
+		Files []Filename `short:"f"`
+	} `command:"add-multi-flag" description:"add multiple items via flags"`
+
 	RemoveCommand struct {
 		Other bool     `short:"o"`
 		File  Filename `short:"f" long:"filename"`
@@ -122,7 +127,7 @@
 		{
 			// Commands
 			[]string{""},
-			[]string{"add", "add-multi", "rename", "rm"},
+			[]string{"add", "add-multi", "add-multi-flag", "rename", "rm"},
 			false,
 		},
 
@@ -130,10 +135,11 @@
 			// Commands with descriptions
 			[]string{""},
 			[]string{
-				"add        # add an item",
-				"add-multi  # add multiple items",
-				"rename     # rename an item",
-				"rm         # remove an item",
+				"add             # add an item",
+				"add-multi       # add multiple items",
+				"add-multi-flag  # add multiple items via flags",
+				"rename          # rename an item",
+				"rm              # remove an item",
 			},
 			true,
 		},
@@ -219,6 +225,12 @@
 			[]string{"hello universe"},
 			false,
 		},
+		{
+			// Multiple flag filename
+			[]string{"add-multi-flag", "-f", filepath.Join(completionTestSourcedir, "completion")},
+			completionTestFilename,
+			false,
+		},
 	}
 }