diff --git a/CHANGELOG.md b/CHANGELOG.md
index a3c1834ddf7..d0fec342e12 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -758,3 +758,8 @@
 - Fixed a bug where the compiler would produce wrong JavaScript code for binary
   pattern matching expressions using literal strings and byte segments.
   ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
+
+- The compiler now provides a clearer error message when a function's return type
+  is mistakenly declared using `:` instead of `->`.
+  ([Gurvir Singh](https://github.com/baraich))
+>>>>>>> Stashed changes
diff --git a/compiler-core/src/parse.rs b/compiler-core/src/parse.rs
index a67c334a6bc..8f4467c84d9 100644
--- a/compiler-core/src/parse.rs
+++ b/compiler-core/src/parse.rs
@@ -2117,6 +2117,22 @@ where
         )?;
         let (_, rpar_e) =
             self.expect_one_following_series(&Token::RightParen, "a function parameter")?;
+
+        // Check for TypeScript-style return type annotation (:) instead of arrow (->)
+        if let Some((colon_start, colon_end)) = self.maybe_one(&Token::Colon) {
+            return Err(ParseError {
+                error: ParseErrorType::UnexpectedToken {
+                    token: Token::Colon,
+                    expected: vec!["`->`".into()],
+                    hint: Some("Return type annotations are written using `->`, not `:`".into()),
+                },
+                location: SrcSpan {
+                    start: colon_start,
+                    end: colon_end,
+                },
+            });
+        };
+
         let return_annotation = self.parse_type_annotation(&Token::RArrow)?;
 
         let (body_start, body, end, end_position) = match self.maybe_one(&Token::LeftBrace) {
diff --git a/compiler-core/src/parse/snapshots/gleam_core__parse__tests__wrong_function_return_type_declaration_using_colon_instead_of_right_arrow.snap b/compiler-core/src/parse/snapshots/gleam_core__parse__tests__wrong_function_return_type_declaration_using_colon_instead_of_right_arrow.snap
new file mode 100644
index 00000000000..f194b3e6773
--- /dev/null
+++ b/compiler-core/src/parse/snapshots/gleam_core__parse__tests__wrong_function_return_type_declaration_using_colon_instead_of_right_arrow.snap
@@ -0,0 +1,19 @@
+---
+source: compiler-core/src/parse/tests.rs
+expression: "\npub fn main(): Nil {}\n        "
+---
+----- SOURCE CODE
+
+pub fn main(): Nil {}
+        
+
+----- ERROR
+error: Syntax error
+  ┌─ /src/parse/error.gleam:2:14
+  │
+2 │ pub fn main(): Nil {}
+  │              ^ I was not expecting this
+
+Found `:`, expected one of: 
+- `->`
+Hint: Return type annotations are written using `->`, not `:`
diff --git a/compiler-core/src/parse/tests.rs b/compiler-core/src/parse/tests.rs
index 23e41843456..f9072bb9787 100644
--- a/compiler-core/src/parse/tests.rs
+++ b/compiler-core/src/parse/tests.rs
@@ -1992,3 +1992,12 @@ pub fn main() {
 "#
     );
 }
+
+#[test]
+fn wrong_function_return_type_declaration_using_colon_instead_of_right_arrow() {
+    assert_module_error!(
+        r#"
+pub fn main(): Nil {}
+        "#
+    );
+}