diff --git a/providers/posflag/posflag.go b/providers/posflag/posflag.go
index e92d430d..5ed7ad00 100644
--- a/providers/posflag/posflag.go
+++ b/providers/posflag/posflag.go
@@ -86,6 +86,12 @@ func (p *Posflag) Read() (map[string]interface{}, error) {
 			val, _ = p.flagset.GetStringSlice(key)
 		case "intSlice":
 			val, _ = p.flagset.GetIntSlice(key)
+		case "stringToString":
+			val, _ = p.flagset.GetStringToString(key)
+		case "stringToInt":
+			val, _ = p.flagset.GetStringToInt(key)
+		case "stringToInt64":
+			val, _ = p.flagset.GetStringToInt64(key)
 		default:
 			val = f.Value.String()
 		}
diff --git a/providers/posflag/posflag_test.go b/providers/posflag/posflag_test.go
index 32c4dd3c..dd68b651 100644
--- a/providers/posflag/posflag_test.go
+++ b/providers/posflag/posflag_test.go
@@ -44,3 +44,31 @@ func TestIssue90(t *testing.T) {
 
 	require.Equal(t, exampleKeys, k.All())
 }
+
+type Maps struct {
+	String map[string]string
+	Int    map[string]int
+	Int64  map[string]int64
+}
+
+func TestIssue100(t *testing.T) {
+	var err error
+	examplePosFlags := &pflag.FlagSet{}
+	examplePosFlags.StringToString("string", map[string]string{"k": "v"}, "")
+	examplePosFlags.StringToInt("int", map[string]int{"k": 1}, "")
+	examplePosFlags.StringToInt64("int64", map[string]int64{"k": 2}, "")
+
+	k := koanf.New(".")
+
+	err = k.Load(posflag.Provider(examplePosFlags, ".", k), nil)
+	require.Nil(t, err)
+
+	maps := new(Maps)
+
+	err = k.Unmarshal("", maps)
+	require.Nil(t, err)
+
+	require.Equal(t, map[string]string{"k": "v"}, maps.String)
+	require.Equal(t, map[string]int{"k": 1}, maps.Int)
+	require.Equal(t, map[string]int64{"k": 2}, maps.Int64)
+}