diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5adb098543..0aadcbf0f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -59,6 +59,7 @@
 - Don't skip Stdlib docstring tests. https://github.com/rescript-lang/rescript/pull/7694
 - Remove all leftovers of `pinned-dependencies` handling. https://github.com/rescript-lang/rescript/pull/7686
 - Add `rust-version` field to Rewatch's `Cargo.toml`. https://github.com/rescript-lang/rescript/pull/7701
+- Rewatch: remove support for .ml(i) and .re(i). https://github.com/rescript-lang/rescript/pull/7727
 
 # 12.0.0-beta.2
 
diff --git a/rewatch/src/build/packages.rs b/rewatch/src/build/packages.rs
index 5fe9627334..92338c4682 100644
--- a/rewatch/src/build/packages.rs
+++ b/rewatch/src/build/packages.rs
@@ -599,7 +599,7 @@ fn extend_with_children(
 /// Make turns a folder, that should contain a config, into a tree of Packages.
 /// It does so in two steps:
 /// 1. Get all the packages parsed, and take all the source folders from the config
-/// 2. Take the (by then deduplicated) packages, and find all the '.re', '.res', '.ml' and
+/// 2. Take the (by then deduplicated) packages, and find all the '.res' and
 ///    interface files.
 ///
 /// The two step process is there to reduce IO overhead
@@ -785,13 +785,11 @@ pub fn parse_packages(build_state: &mut BuildState) {
                                 is_type_dev: metadata.is_type_dev,
                             });
                     } else {
-                        // remove last character of string: resi -> res, rei -> re, mli -> ml
+                        // remove last character of string: resi -> res
                         let mut implementation_filename = file.to_owned();
                         let extension = implementation_filename.extension().unwrap().to_str().unwrap();
                         implementation_filename = match extension {
                             "resi" => implementation_filename.with_extension("res"),
-                            "rei" => implementation_filename.with_extension("re"),
-                            "mli" => implementation_filename.with_extension("ml"),
                             _ => implementation_filename,
                         };
                         match source_files.get(&implementation_filename) {
diff --git a/rewatch/src/helpers.rs b/rewatch/src/helpers.rs
index 04427a8df1..456a43cdae 100644
--- a/rewatch/src/helpers.rs
+++ b/rewatch/src/helpers.rs
@@ -306,11 +306,11 @@ pub fn get_system_time() -> u128 {
 }
 
 pub fn is_interface_file(extension: &str) -> bool {
-    matches!(extension, "resi" | "mli" | "rei")
+    extension == "resi"
 }
 
 pub fn is_implementation_file(extension: &str) -> bool {
-    matches!(extension, "res" | "ml" | "re")
+    extension == "res"
 }
 
 pub fn is_source_file(extension: &str) -> bool {