diff --git a/crates/aiken-lang/src/parser/expr/when/clause.rs b/crates/aiken-lang/src/parser/expr/when/clause.rs
index 4eaf09f9..262f8e49 100644
--- a/crates/aiken-lang/src/parser/expr/when/clause.rs
+++ b/crates/aiken-lang/src/parser/expr/when/clause.rs
@@ -11,7 +11,17 @@ pub fn parser(
     expression: Recursive<'_, Token, UntypedExpr, ParseError>,
 ) -> impl Parser<Token, ast::UntypedClause, Error = ParseError> + '_ {
     pattern()
-        .then(just(Token::Vbar).ignore_then(pattern()).repeated().or_not())
+        .then(
+            choice((
+                just(Token::Vbar),
+                just(Token::VbarVbar),
+                just(Token::Or),
+                just(Token::Comma),
+            ))
+            .ignore_then(pattern())
+            .repeated()
+            .or_not(),
+        )
         .then(choice((just(Token::If)
             .ignore_then(guard())
             .or_not()
@@ -76,4 +86,18 @@ mod tests {
             "#
         );
     }
+
+    #[test]
+    fn when_clause_alternative() {
+        assert_expr!(
+            r#"
+            when val is {
+              Bar1{..} | Bar2{..} -> todo
+              Bar3{..} || Bar4{..} -> todo
+              Bar5{..} or Bar6{..} -> todo
+              Bar5{..}, Bar6{..} -> todo
+            }
+            "#
+        );
+    }
 }
diff --git a/crates/aiken-lang/src/parser/expr/when/snapshots/when_clause_alternative.snap b/crates/aiken-lang/src/parser/expr/when/snapshots/when_clause_alternative.snap
new file mode 100644
index 00000000..7c3245a8
--- /dev/null
+++ b/crates/aiken-lang/src/parser/expr/when/snapshots/when_clause_alternative.snap
@@ -0,0 +1,177 @@
+---
+source: crates/aiken-lang/src/parser/expr/when/clause.rs
+description: "Code:\n\nwhen val is {\n  Bar1{..} | Bar2{..} -> todo\n  Bar3{..} || Bar4{..} -> todo\n  Bar5{..} or Bar6{..} -> todo\n  Bar5{..}, Bar6{..} -> todo\n}\n"
+---
+When {
+    location: 0..136,
+    subject: Var {
+        location: 5..8,
+        name: "val",
+    },
+    clauses: [
+        UntypedClause {
+            location: 16..43,
+            patterns: [
+                Constructor {
+                    is_record: true,
+                    location: 16..24,
+                    name: "Bar1",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        21..23,
+                    ),
+                    tipo: (),
+                },
+                Constructor {
+                    is_record: true,
+                    location: 27..35,
+                    name: "Bar2",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        32..34,
+                    ),
+                    tipo: (),
+                },
+            ],
+            then: Trace {
+                kind: Todo,
+                location: 39..43,
+                then: ErrorTerm {
+                    location: 39..43,
+                },
+                label: String {
+                    location: 39..43,
+                    value: "aiken::todo",
+                },
+                arguments: [],
+            },
+        },
+        UntypedClause {
+            location: 46..74,
+            patterns: [
+                Constructor {
+                    is_record: true,
+                    location: 46..54,
+                    name: "Bar3",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        51..53,
+                    ),
+                    tipo: (),
+                },
+                Constructor {
+                    is_record: true,
+                    location: 58..66,
+                    name: "Bar4",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        63..65,
+                    ),
+                    tipo: (),
+                },
+            ],
+            then: Trace {
+                kind: Todo,
+                location: 70..74,
+                then: ErrorTerm {
+                    location: 70..74,
+                },
+                label: String {
+                    location: 70..74,
+                    value: "aiken::todo",
+                },
+                arguments: [],
+            },
+        },
+        UntypedClause {
+            location: 77..105,
+            patterns: [
+                Constructor {
+                    is_record: true,
+                    location: 77..85,
+                    name: "Bar5",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        82..84,
+                    ),
+                    tipo: (),
+                },
+                Constructor {
+                    is_record: true,
+                    location: 89..97,
+                    name: "Bar6",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        94..96,
+                    ),
+                    tipo: (),
+                },
+            ],
+            then: Trace {
+                kind: Todo,
+                location: 101..105,
+                then: ErrorTerm {
+                    location: 101..105,
+                },
+                label: String {
+                    location: 101..105,
+                    value: "aiken::todo",
+                },
+                arguments: [],
+            },
+        },
+        UntypedClause {
+            location: 108..134,
+            patterns: [
+                Constructor {
+                    is_record: true,
+                    location: 108..116,
+                    name: "Bar5",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        113..115,
+                    ),
+                    tipo: (),
+                },
+                Constructor {
+                    is_record: true,
+                    location: 118..126,
+                    name: "Bar6",
+                    arguments: [],
+                    module: None,
+                    constructor: (),
+                    spread_location: Some(
+                        123..125,
+                    ),
+                    tipo: (),
+                },
+            ],
+            then: Trace {
+                kind: Todo,
+                location: 130..134,
+                then: ErrorTerm {
+                    location: 130..134,
+                },
+                label: String {
+                    location: 130..134,
+                    value: "aiken::todo",
+                },
+                arguments: [],
+            },
+        },
+    ],
+}
diff --git a/crates/aiken-project/src/lib.rs b/crates/aiken-project/src/lib.rs
index 1ffc6160..5e6bd222 100644
--- a/crates/aiken-project/src/lib.rs
+++ b/crates/aiken-project/src/lib.rs
@@ -812,6 +812,10 @@ where
                     &mut self.data_types,
                 )?;
 
+                if name == "foo" {
+                    println!("{:#?}", checked_module.ast);
+                }
+
                 if our_modules.contains(checked_module.name.as_str()) {
                     self.warnings.extend(warnings);
                 }