diff --git a/config/config.go b/config/config.go
index 3d73d69e..dd4c4b88 100644
--- a/config/config.go
+++ b/config/config.go
@@ -109,6 +109,10 @@ func (k *KoanfAdapter) Unmarshal(path string, o interface{}) error {
 			Result:           o,
 			ErrorUnused:      true,
 			WeaklyTypedInput: true,
+			DecodeHook: mapstructure.ComposeDecodeHookFunc(
+				mapstructure.StringToTimeDurationHookFunc(),
+				stringToConfigDurationHookFunc(),
+			),
 		},
 	})
 }
@@ -239,3 +243,28 @@ func (m MapAdapter) Route(s string) contract.ConfigAccessor {
 		panic(fmt.Sprintf("value at path %s is not a valid Router", s))
 	}
 }
+
+func stringToConfigDurationHookFunc() mapstructure.DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if t != reflect.TypeOf(Duration{}) {
+			return data, nil
+		}
+		var val string
+		if f.Kind() == reflect.Float64 {
+			val = fmt.Sprintf("%v", data)
+		} else if f.Kind() == reflect.String {
+			val = fmt.Sprintf(`"%v"`, data)
+		} else {
+			return nil, fmt.Errorf("expected a %s, should be float64 or string, got '%s'", t.String(), f.String())
+		}
+		d := Duration{}
+		err := d.UnmarshalJSON([]byte(val))
+		if err != nil {
+			return nil, err
+		}
+		return d, nil
+	}
+}
diff --git a/config/config_test.go b/config/config_test.go
index 0e9263e7..8b70fbd5 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -116,6 +116,15 @@ func TestKoanfAdapter_Unmarshal(t *gotesting.T) {
 	err := ka.Unmarshal("foo.bar", &target)
 	assert.NoError(t, err)
 	assert.Equal(t, "baz", target)
+
+	var r Duration
+	err = ka.Unmarshal("duration_string", &r)
+	assert.NoError(t, err)
+	assert.Equal(t, r, Duration{1 * time.Second})
+
+	err = ka.Unmarshal("duration_number", &r)
+	assert.NoError(t, err)
+	assert.Equal(t, r, Duration{1 * time.Nanosecond})
 }
 
 func TestMapAdapter_Bool(t *gotesting.T) {
diff --git a/config/testdata/mock.json b/config/testdata/mock.json
index fa730a3e..72873e4f 100644
--- a/config/testdata/mock.json
+++ b/config/testdata/mock.json
@@ -1,10 +1,12 @@
-{
-  "foo": {
-    "bar": "baz"
-  },
-  "bool": true,
-  "string": "string",
-  "int": 42,
-  "strings": ["foo", "bar"],
-  "float": 1.0
-}
+{
+  "foo": {
+    "bar": "baz"
+  },
+  "bool": true,
+  "string": "string",
+  "int": 42,
+  "strings": ["foo", "bar"],
+  "float": 1.0,
+  "duration_string": "1s",
+  "duration_number": 1
+}