diff --git a/modules/reitit-core/src/reitit/core.cljc b/modules/reitit-core/src/reitit/core.cljc
index bcd54ac4..8b62909a 100644
--- a/modules/reitit-core/src/reitit/core.cljc
+++ b/modules/reitit-core/src/reitit/core.cljc
@@ -360,7 +360,8 @@
   | `:validate`  | Function of `routes opts => ()` to validate route (data) via side-effects
   | `:conflicts` | Function of `{route #{route}} => ()` to handle conflicting routes
   | `:exception` | Function of `Exception => Exception ` to handle creation time exceptions (default `reitit.exception/exception`)
-  | `:router`    | Function of `routes opts => router` to override the actual router implementation"
+  | `:router`    | Function of `routes opts => router` to override the actual router implementation
+  | `:merge`     | Function of `route-data key value` to add new kv pair to route-data map. Default uses merge-merge."
   ([raw-routes]
    (router raw-routes {}))
   ([raw-routes opts]
diff --git a/modules/reitit-core/src/reitit/impl.cljc b/modules/reitit-core/src/reitit/impl.cljc
index 7d3729bb..7bd7bb70 100644
--- a/modules/reitit-core/src/reitit/impl.cljc
+++ b/modules/reitit-core/src/reitit/impl.cljc
@@ -4,9 +4,7 @@
             [clojure.set :as set]
             [meta-merge.core :as mm]
             [reitit.trie :as trie]
-            [reitit.exception :as ex]
-            ;; FIXME: Can't be used directly, should be option enabled by malli coercion
-            malli.util)
+            [reitit.exception :as ex])
   #?(:clj
      (:import (java.util HashMap Map)
               (java.net URLEncoder URLDecoder))))
@@ -62,21 +60,21 @@
 (defn map-data [f routes]
   (mapv (fn [[p ds]] [p (f p ds)]) routes))
 
-(defn merge-data [p x]
+(defn default-route-data-merge [acc k v]
+  (mm/meta-merge acc {k v}))
+
+(defn merge-data [route-data-merge p x]
   (reduce
     (fn [acc [k v]]
       (try
-        (case k
-          ;; TODO: Make this enabled from malli coercion
-          ;; TODO: Schema & spec
-          :parameters (assoc acc :parameters (merge-with malli.util/merge (:parameters acc) v))
-          (mm/meta-merge acc {k v}))
+        (route-data-merge acc k v)
         (catch #?(:clj Exception, :cljs js/Error) e
           (ex/fail! ::merge-data {:path p, :left acc, :right {k v}, :exception e}))))
     {} x))
 
-(defn resolve-routes [raw-routes {:keys [coerce] :as opts}]
-  (cond->> (->> (walk raw-routes opts) (map-data merge-data))
+(defn resolve-routes [raw-routes {:keys [coerce _merge] :as opts}]
+  (cond->> (->> (walk raw-routes opts)
+                (map-data (partial merge-data (or (:merge opts) default-route-data-merge))))
            coerce (into [] (keep #(coerce % opts)))))
 
 (defn path-conflicting-routes [routes opts]
diff --git a/modules/reitit-malli/src/reitit/coercion/malli.cljc b/modules/reitit-malli/src/reitit/coercion/malli.cljc
index ee4a4bdc..9c06a518 100644
--- a/modules/reitit-malli/src/reitit/coercion/malli.cljc
+++ b/modules/reitit-malli/src/reitit/coercion/malli.cljc
@@ -7,7 +7,8 @@
             [malli.swagger :as swagger]
             [malli.core :as m]
             [clojure.set :as set]
-            [clojure.walk :as walk]))
+            [clojure.walk :as walk]
+            [meta-merge.core :as mm]))
 
 ;;
 ;; coercion
@@ -182,3 +183,8 @@
          (-coercer (compile schema options) :response transformers :encode opts))))))
 
 (def coercion (create default-options))
+
+(defn route-data-merge [acc k v]
+  (case k
+    :parameters (assoc acc :parameters (merge-with mu/merge (:parameters acc) v))
+    (mm/meta-merge acc {k v})))
diff --git a/test/cljc/reitit/impl_test.cljc b/test/cljc/reitit/impl_test.cljc
index 8a1fb948..48cfe5bf 100644
--- a/test/cljc/reitit/impl_test.cljc
+++ b/test/cljc/reitit/impl_test.cljc
@@ -1,6 +1,9 @@
 (ns reitit.impl-test
   (:require [clojure.test :refer [deftest testing is are]]
-            [reitit.impl :as impl]))
+            [reitit.impl :as impl]
+            [reitit.coercion.malli :as rcm]
+            [malli.core :as m]
+            [schema.core :as schema]))
 
 (deftest strip-nils-test
   (is (= {:a 1, :c false} (impl/strip-nils {:a 1, :b nil, :c false}))))
@@ -173,7 +176,8 @@
 (deftest merge-data-test
   (is (= {:view 'b
           :controllers [1 2]}
-         (impl/merge-data "/"
+         (impl/merge-data impl/default-route-data-merge
+                          "/"
                           [[:view 'a]
                            [:controllers [1]]
                            [:view 'b]
@@ -181,21 +185,32 @@
 
   (is (= {:view 'b
           :controllers [2]}
-         (impl/merge-data "/"
+         (impl/merge-data impl/default-route-data-merge
+                          "/"
                           [[:view 'a]
                            [:controllers [1]]
                            [:view 'b]
                            [:controllers ^:replace [2]]])))
 
+  (is (= {:a schema/Str
+          :b schema/Str}
+         (-> (impl/merge-data rcm/route-data-merge
+                              "/"
+                              [[:parameters {:path {:a schema/Str}}]
+                               [:parameters {:path {:b schema/Str}}]])
+             :parameters
+             :path)))
+
   (is (= [:map
           [:a 'string?]
           [:b 'int?]]
-         (-> (impl/merge-data "/"
+         (-> (impl/merge-data rcm/route-data-merge
+                              "/"
                               [[:parameters {:path [:map [:a 'string?]]}]
                                [:parameters {:path [:map [:b 'int?]]}]])
              :parameters
              :path
-             ;; Merge returns schmea object, convert back to form for comparison
+             ;; Merge returns schema object, convert back to form for comparison
              malli.core/form)))
 
   ;; TODO: Also test and support Schema and spec merging