diff --git a/viper.go b/viper.go
index 46b1a85..d7a3fad 100644
--- a/viper.go
+++ b/viper.go
@@ -1404,11 +1404,13 @@ func (v *Viper) realKey(key string) string {
 func InConfig(key string) bool { return v.InConfig(key) }
 
 func (v *Viper) InConfig(key string) bool {
-	// if the requested key is an alias, then return the proper key
-	key = v.realKey(key)
+	lcaseKey := strings.ToLower(key)
 
-	_, exists := v.config[key]
-	return exists
+	// if the requested key is an alias, then return the proper key
+	lcaseKey = v.realKey(lcaseKey)
+	path := strings.Split(lcaseKey, v.keyDelim)
+
+	return v.searchIndexableWithPathPrefixes(v.config, path) != nil
 }
 
 // SetDefault sets the default value for this key.
diff --git a/viper_test.go b/viper_test.go
index 4192748..080d0c4 100644
--- a/viper_test.go
+++ b/viper_test.go
@@ -382,7 +382,9 @@ func TestUnmarshaling(t *testing.T) {
 
 	unmarshalReader(r, v.config)
 	assert.True(t, InConfig("name"))
+	assert.True(t, InConfig("clothing.jacket"))
 	assert.False(t, InConfig("state"))
+	assert.False(t, InConfig("clothing.hat"))
 	assert.Equal(t, "steve", Get("name"))
 	assert.Equal(t, []interface{}{"skateboarding", "snowboarding", "go"}, Get("hobbies"))
 	assert.Equal(t, map[string]interface{}{"jacket": "leather", "trousers": "denim", "pants": map[string]interface{}{"size": "large"}}, Get("clothing"))
@@ -1239,7 +1241,9 @@ func TestReadBufConfig(t *testing.T) {
 	t.Log(v.AllKeys())
 
 	assert.True(t, v.InConfig("name"))
+	assert.True(t, v.InConfig("clothing.jacket"))
 	assert.False(t, v.InConfig("state"))
+	assert.False(t, v.InConfig("clothing.hat"))
 	assert.Equal(t, "steve", v.Get("name"))
 	assert.Equal(t, []interface{}{"skateboarding", "snowboarding", "go"}, v.Get("hobbies"))
 	assert.Equal(t, map[string]interface{}{"jacket": "leather", "trousers": "denim", "pants": map[string]interface{}{"size": "large"}}, v.Get("clothing"))