diff --git a/src/internal/config.ts b/src/internal/config.ts
index 45b30a0dd0..31de7e244c 100644
--- a/src/internal/config.ts
+++ b/src/internal/config.ts
@@ -1,3 +1,5 @@
+let _enable_super_gross_mode_that_will_cause_bad_things = false;
+
 /**
  * The global configuration object for RxJS, used to configure things
  * like what Promise contructor should used to create Promises
@@ -17,5 +19,17 @@ export const config = {
    * an unhandled error. DO NOT USE THIS FLAG UNLESS IT'S NEEDED TO BY TIME
    * FOR MIGRATION REASONS.
    */
-  useDeprecatedSynchronousErrorHandling: false,
+  set useDeprecatedSynchronousErrorHandling(value: boolean) {
+    if (value) {
+      const error = new Error();
+      console.warn('DEPRECATED! RxJS was set to use deprecated synchronous error handling behavior by code at: \n' + error.stack);
+    } else if (_enable_super_gross_mode_that_will_cause_bad_things) {
+      console.log('RxJS: Back to a better error behavior. Thank you. <3');
+    }
+    _enable_super_gross_mode_that_will_cause_bad_things = value;
+  },
+
+  get useDeprecatedSynchronousErrorHandling() {
+    return _enable_super_gross_mode_that_will_cause_bad_things;
+  }
 };