diff --git a/graphqxl_parser/src/ast_arguments.rs b/graphqxl_parser/src/ast_arguments.rs
index 5ac5305..06b5667 100644
--- a/graphqxl_parser/src/ast_arguments.rs
+++ b/graphqxl_parser/src/ast_arguments.rs
@@ -6,13 +6,20 @@ use crate::utils::{unknown_rule_error, OwnedSpan};
 use crate::{parse_directive, parse_value_type, Directive, ValueType};
 use pest::iterators::Pair;
 
+#[derive(Debug, Clone, PartialEq)]
+pub enum ArgumentDefaultValue {
+    None,
+    ValueData(ValueData),
+    Identifier(Identifier),
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct Argument {
     pub span: OwnedSpan,
     pub name: Identifier,
     pub description: String,
     pub value_type: ValueType,
-    pub default: Option<ValueData>,
+    pub default: ArgumentDefaultValue,
     pub directives: Vec<Directive>,
 }
 
@@ -23,7 +30,7 @@ impl Argument {
             name: Identifier::from(name),
             description: "".to_string(),
             value_type: t,
-            default: None,
+            default: ArgumentDefaultValue::None,
             directives: Vec::new(),
         }
     }
@@ -53,8 +60,8 @@ impl Argument {
         self.clone()
     }
 
-    pub fn default(&mut self, value_data: ValueData) -> Self {
-        self.default = Some(value_data);
+    pub fn default(&mut self, default: ArgumentDefaultValue) -> Self {
+        self.default = default;
         self.clone()
     }
 
@@ -75,11 +82,13 @@ fn parse_argument(pair: Pair<Rule>, file: &str) -> Result<Argument, Box<RuleErro
             // at this moment we are on [identifier, value]
             let name = parse_identifier(next.unwrap(), file)?;
             let value = parse_value_type(childs.next().unwrap(), file)?;
-            let mut default = None;
+            let mut default = ArgumentDefaultValue::None;
             let mut directives = Vec::new();
             if let Some(pair) = childs.next() {
                 if let Rule::value_data = pair.as_rule() {
-                    default = Some(parse_value_data(pair, file)?)
+                    default = ArgumentDefaultValue::ValueData(parse_value_data(pair, file)?)
+                } else if let Rule::identifier = pair.as_rule() {
+                    default = ArgumentDefaultValue::Identifier(parse_identifier(pair, file)?)
                 }
                 for directive in childs {
                     directives.push(parse_directive(directive, file)?);
@@ -154,9 +163,19 @@ mod tests {
     fn test_default_value_for_argument_works() {
         assert_eq!(
             parse_input("(arg: String = \"default\")"),
-            Ok(vec![
-                Argument::string("arg").default(ValueData::string("default"))
-            ])
+            Ok(vec![Argument::string("arg").default(
+                ArgumentDefaultValue::ValueData(ValueData::string("default"))
+            )])
+        );
+    }
+
+    #[test]
+    fn test_default_value_as_identifier_for_argument_works() {
+        assert_eq!(
+            parse_input("(arg: String = Foo)"),
+            Ok(vec![Argument::string("arg").default(
+                ArgumentDefaultValue::Identifier(Identifier::from("Foo"))
+            )])
         );
     }
 
@@ -165,7 +184,9 @@ mod tests {
         assert_eq!(
             parse_input("(arg: String = \"default\" @dir1 @dir2)"),
             Ok(vec![Argument::string("arg")
-                .default(ValueData::string("default"))
+                .default(ArgumentDefaultValue::ValueData(ValueData::string(
+                    "default"
+                )))
                 .directive(Directive::build("dir1"))
                 .directive(Directive::build("dir2"))])
         );
diff --git a/graphqxl_parser/src/ast_block_field.rs b/graphqxl_parser/src/ast_block_field.rs
index 0749334..fa1d96c 100644
--- a/graphqxl_parser/src/ast_block_field.rs
+++ b/graphqxl_parser/src/ast_block_field.rs
@@ -120,6 +120,7 @@ mod tests {
     use super::*;
     use crate::ast_value_data::ValueData;
     use crate::utils::parse_full_input;
+    use crate::ArgumentDefaultValue;
 
     fn parse_with_args_input(input: &str) -> Result<BlockField, Box<RuleError>> {
         parse_full_input(input, Rule::field_with_args, parse_block_field)
@@ -198,8 +199,9 @@ mod tests {
             Ok(BlockField::build("field")
                 .string()
                 .arg(
-                    Argument::build("arg1", ValueType::string().array().non_nullable())
-                        .default(ValueData::string("default").list())
+                    Argument::build("arg1", ValueType::string().array().non_nullable()).default(
+                        ArgumentDefaultValue::ValueData(ValueData::string("default").list())
+                    )
                 )
                 .arg(Argument::build("arg2", ValueType::float().non_nullable())))
         );
diff --git a/graphqxl_parser/src/grammar.pest b/graphqxl_parser/src/grammar.pest
index 54d66da..8a624e5 100644
--- a/graphqxl_parser/src/grammar.pest
+++ b/graphqxl_parser/src/grammar.pest
@@ -77,7 +77,7 @@ field_without_args = { description? ~ identifier ~ ":" ~ value_type ~ directive*
 field_without_args_without_value = { description? ~ identifier ~ directive* }
 
 arguments = { "(" ~ argument* ~ ")" }
-    argument = { description? ~ identifier ~ ":" ~ value_type ~ ("=" ~ value_data)? ~ directive* }
+    argument = { description? ~ identifier ~ ":" ~ value_type ~ ("=" ~ (value_data | identifier))? ~ directive* }
 
 function_call = { "(" ~ function_input+ ~ ")" }
     function_input = { identifier ~ ":" ~ value_data }
diff --git a/graphqxl_synthesizer/src/synth_arguments.rs b/graphqxl_synthesizer/src/synth_arguments.rs
index e988958..ef355d7 100644
--- a/graphqxl_synthesizer/src/synth_arguments.rs
+++ b/graphqxl_synthesizer/src/synth_arguments.rs
@@ -1,10 +1,11 @@
 use crate::synth_directive::DirectiveSynth;
+use crate::synth_identifier::IdentifierSynth;
 use crate::synth_value_data::ValueDataSynth;
 use crate::synth_value_type::ValueTypeSynth;
 use crate::synths::{
     ChainSynth, MultilineListSynth, OneLineListSynth, StringSynth, Synth, SynthContext,
 };
-use graphqxl_parser::Argument;
+use graphqxl_parser::{Argument, ArgumentDefaultValue};
 
 pub(crate) struct ArgumentsSynth(pub(crate) Vec<Argument>);
 
@@ -18,10 +19,14 @@ impl Synth for ArgumentsSynth {
                     Box::new(StringSynth(argument.name.id.clone() + ": ")),
                     Box::new(ValueTypeSynth(argument.value_type.clone())),
                 ];
-                if let Some(default) = &argument.default {
+                if let ArgumentDefaultValue::ValueData(default) = &argument.default {
                     v.push(Box::new(StringSynth::from(" = ")));
                     v.push(Box::new(ValueDataSynth(default.clone())));
+                } else if let ArgumentDefaultValue::Identifier(default) = &argument.default {
+                    v.push(Box::new(StringSynth::from(" = ")));
+                    v.push(Box::new(IdentifierSynth(default.clone())));
                 }
+
                 for directive in argument.directives.iter() {
                     v.push(Box::new(StringSynth::from(" ")));
                     v.push(Box::new(DirectiveSynth(directive.clone())));
@@ -68,7 +73,9 @@ mod tests {
 
     #[test]
     fn test_with_default_value() {
-        let synth = ArgumentsSynth(vec![Argument::int("arg").default(ValueData::int(1).list())]);
+        let synth =
+            ArgumentsSynth(vec![Argument::int("arg")
+                .default(ArgumentDefaultValue::ValueData(ValueData::int(1).list()))]);
         assert_eq!(synth.synth_zero(), "(arg: Int = [ 1 ])")
     }
 
@@ -81,7 +88,7 @@ mod tests {
     #[test]
     fn test_with_default_value_with_directives() {
         let synth = ArgumentsSynth(vec![Argument::int("arg")
-            .default(ValueData::int(1).list())
+            .default(ArgumentDefaultValue::ValueData(ValueData::int(1).list()))
             .directive(Directive::build("dir"))]);
         assert_eq!(synth.synth_zero(), "(arg: Int = [ 1 ] @dir)")
     }
diff --git a/src/test/default-arg.graphqxl b/src/test/default-arg.graphqxl
new file mode 100644
index 0000000..edb3e64
--- /dev/null
+++ b/src/test/default-arg.graphqxl
@@ -0,0 +1,8 @@
+enum Enum {
+    One
+    Other
+}
+
+type Query {
+    foo(bar: Enum! = One): Boolean
+}
diff --git a/src/test/default-arg.graphqxl.result b/src/test/default-arg.graphqxl.result
new file mode 100644
index 0000000..dbe6883
--- /dev/null
+++ b/src/test/default-arg.graphqxl.result
@@ -0,0 +1,9 @@
+enum Enum {
+  One
+  Other
+}
+
+type Query {
+  foo(bar: Enum! = One): Boolean
+}
+