diff --git a/viper.go b/viper.go
index 6c1bcae..9e2e353 100644
--- a/viper.go
+++ b/viper.go
@@ -105,6 +105,9 @@ func init() {
 
 		encoderRegistry.RegisterEncoder("hcl", codec)
 		decoderRegistry.RegisterDecoder("hcl", codec)
+
+		encoderRegistry.RegisterEncoder("tfvars", codec)
+		decoderRegistry.RegisterDecoder("tfvars", codec)
 	}
 }
 
@@ -329,7 +332,7 @@ func NewWithOptions(opts ...Option) *Viper {
 // can use it in their testing as well.
 func Reset() {
 	v = New()
-	SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "dotenv", "env", "ini"}
+	SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "tfvars", "dotenv", "env", "ini"}
 	SupportedRemoteProviders = []string{"etcd", "consul", "firestore"}
 }
 
@@ -368,7 +371,7 @@ type RemoteProvider interface {
 }
 
 // SupportedExts are universally supported extensions.
-var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "dotenv", "env", "ini"}
+var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "tfvars", "dotenv", "env", "ini"}
 
 // SupportedRemoteProviders are universally supported remote providers.
 var SupportedRemoteProviders = []string{"etcd", "consul", "firestore"}
@@ -1624,7 +1627,7 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 	buf.ReadFrom(in)
 
 	switch format := strings.ToLower(v.getConfigType()); format {
-	case "yaml", "yml", "json", "toml", "hcl":
+	case "yaml", "yml", "json", "toml", "hcl", "tfvars":
 		err := decoderRegistry.Decode(format, buf.Bytes(), &c)
 		if err != nil {
 			return ConfigParseError{err}
@@ -1681,7 +1684,7 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 func (v *Viper) marshalWriter(f afero.File, configType string) error {
 	c := v.AllSettings()
 	switch configType {
-	case "yaml", "yml", "json", "toml", "hcl":
+	case "yaml", "yml", "json", "toml", "hcl", "tfvars":
 		b, err := encoderRegistry.Encode(configType, c)
 		if err != nil {
 			return ConfigMarshalError{err}