diff --git a/backend/Cargo.lock b/backend/Cargo.lock
index 76fd67296b..5179ccf80a 100644
--- a/backend/Cargo.lock
+++ b/backend/Cargo.lock
@@ -4892,6 +4892,7 @@ dependencies = [
  "lazy_static",
  "phf",
  "regex",
+ "serde_json",
  "unicode-general-category",
  "windmill-common",
  "windmill-parser",
diff --git a/backend/parsers/windmill-parser-bash/Cargo.toml b/backend/parsers/windmill-parser-bash/Cargo.toml
index 0ae341ef8b..22579e82c3 100644
--- a/backend/parsers/windmill-parser-bash/Cargo.toml
+++ b/backend/parsers/windmill-parser-bash/Cargo.toml
@@ -16,4 +16,5 @@ unicode-general-category.workspace = true
 itertools.workspace = true
 anyhow.workspace = true
 regex.workspace = true
-lazy_static.workspace = true
\ No newline at end of file
+lazy_static.workspace = true
+serde_json.workspace = true
\ No newline at end of file
diff --git a/backend/parsers/windmill-parser-bash/src/lib.rs b/backend/parsers/windmill-parser-bash/src/lib.rs
index fdd5f26fe6..a43e079cb7 100644
--- a/backend/parsers/windmill-parser-bash/src/lib.rs
+++ b/backend/parsers/windmill-parser-bash/src/lib.rs
@@ -1,6 +1,8 @@
 #![allow(non_snake_case)] // TODO: switch to parse_* function naming
 
+use anyhow::anyhow;
 use regex::Regex;
+use serde_json::json;
 
 use std::collections::HashMap;
 use windmill_parser::{Arg, MainArgSignature, Typ};
@@ -17,19 +19,32 @@ pub fn parse_bash_sig(code: &str) -> windmill_common::error::Result<MainArgSigna
     }
 }
 
+lazy_static::lazy_static! {
+    static ref RE: Regex = Regex::new(r#"(?m)^(\w+)="\$(?:(\d+)|\{(\d+):-(.*)\})"$"#).unwrap();
+}
+
 fn parse_file(code: &str) -> anyhow::Result<Option<Vec<Arg>>> {
-    let mut hm = HashMap::new();
-    let re = Regex::new(r#"(?m)^(\w+)="\$(\d+)"$"#).unwrap();
-    for cap in re.captures_iter(code) {
-        hm.insert(cap[2].parse::<i32>()?, cap[1].to_string());
+    let mut hm: HashMap<i32, (String, Option<String>)> = HashMap::new();
+    for cap in RE.captures_iter(code) {
+        hm.insert(
+            cap.get(2)
+                .or(cap.get(3))
+                .and_then(|x| x.as_str().parse::<i32>().ok())
+                .ok_or_else(|| anyhow!("Impossible to parse arg digit"))?,
+            (
+                cap[1].to_string(),
+                cap.get(4).map(|x| x.as_str().to_string()),
+            ),
+        );
     }
     let mut args = vec![];
     for i in 1..20 {
         if hm.contains_key(&i) {
+            let (name, default) = hm.get(&i).unwrap();
             args.push(Arg {
-                name: hm[&i].clone(),
+                name: name.clone(),
                 typ: Typ::Str(None),
-                default: None,
+                default: default.clone().map(|x| json!(x)),
                 otyp: None,
                 has_default: false,
             });
@@ -43,6 +58,8 @@ fn parse_file(code: &str) -> anyhow::Result<Option<Vec<Arg>>> {
 #[cfg(test)]
 mod tests {
 
+    use serde_json::json;
+
     use super::*;
 
     #[test]
@@ -50,8 +67,7 @@ mod tests {
         let code = r#"
 token="$1"
 image="$2"
-digest="${3:-latest}"
-foo="$4"
+digest="${3:-latest with spaces}"
 
 "#;
         //println!("{}", serde_json::to_string()?);
@@ -74,6 +90,13 @@ foo="$4"
                         typ: Typ::Str(None),
                         default: None,
                         has_default: false
+                    },
+                    Arg {
+                        otyp: None,
+                        name: "digest".to_string(),
+                        typ: Typ::Str(None),
+                        default: Some(json!("latest with spaces")),
+                        has_default: false
                     }
                 ]
             }
diff --git a/frontend/src/lib/script_helpers.ts b/frontend/src/lib/script_helpers.ts
index c254c43615..b017334d3d 100644
--- a/frontend/src/lib/script_helpers.ts
+++ b/frontend/src/lib/script_helpers.ts
@@ -114,6 +114,7 @@ export async function main(
 
 export const BASH_INIT_CODE = `# arguments of the form X="$I" are parsed as parameters X of type string
 msg="$1"
+dflt="\${2:-default value}"
 
 # the last line of the stdout is the return value
 echo "Hello $msg"