diff --git a/CHANGELOG.md b/CHANGELOG.md
index e768b75c53..4db4967e0b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,12 @@
 
 # 12.0.0-alpha.11 (Unreleased)
 
+#### :bug: Bug fix
+
+- Fix `Error.fromException`. https://github.com/rescript-lang/rescript/pull/7364
+
+# 12.0.0-alpha.10
+
 #### :rocket: New Feature
 
 - Add `Dict.has` and double `Dict.forEachWithKey`/`Dict.mapValues` performance. https://github.com/rescript-lang/rescript/pull/7316
diff --git a/lib/es6/Stdlib_Error.js b/lib/es6/Stdlib_Error.js
index d13d973069..9dcb2bfa59 100644
--- a/lib/es6/Stdlib_Error.js
+++ b/lib/es6/Stdlib_Error.js
@@ -1,13 +1,13 @@
 
 
+import * as Stdlib_Exn from "./Stdlib_Exn.js";
 import * as Primitive_option from "./Primitive_option.js";
 
 function fromException(exn) {
-  if (exn.TAG === "Ok") {
-    return;
-  } else {
-    return Primitive_option.some(exn._0);
+  if (exn.RE_EXN_ID === Stdlib_Exn.$$Error) {
+    return Primitive_option.some(exn._1);
   }
+  
 }
 
 let $$EvalError = {};
diff --git a/lib/js/Stdlib_Error.js b/lib/js/Stdlib_Error.js
index 07130c548e..3c6de75afb 100644
--- a/lib/js/Stdlib_Error.js
+++ b/lib/js/Stdlib_Error.js
@@ -1,13 +1,13 @@
 'use strict';
 
+let Stdlib_Exn = require("./Stdlib_Exn.js");
 let Primitive_option = require("./Primitive_option.js");
 
 function fromException(exn) {
-  if (exn.TAG === "Ok") {
-    return;
-  } else {
-    return Primitive_option.some(exn._0);
+  if (exn.RE_EXN_ID === Stdlib_Exn.$$Error) {
+    return Primitive_option.some(exn._1);
   }
+  
 }
 
 let $$EvalError = {};
diff --git a/runtime/Stdlib_Error.res b/runtime/Stdlib_Error.res
index f2035d178d..aaf799a143 100644
--- a/runtime/Stdlib_Error.res
+++ b/runtime/Stdlib_Error.res
@@ -2,7 +2,7 @@ type t = Stdlib_Exn.t
 
 let fromException: exn => option<t> = exn =>
   switch Obj.magic(exn) {
-  | Error(t) => Some(t)
+  | Stdlib_Exn.Error(t) => Some(t)
   | _ => None
   }
 external toException: t => exn = "%identity"