diff --git a/src/malli/core.cljc b/src/malli/core.cljc
index 11af76d2c..26e9bb84b 100644
--- a/src/malli/core.cljc
+++ b/src/malli/core.cljc
@@ -231,7 +231,7 @@
                       (explainer x in acc))
                     acc explainers)))))
           (-transformer [this transformer context]
-            (let [key-transformer (-transformer (map-key) transformer context)
+            (let [key-transformer (-transformer (map-key this) transformer context)
                   value-transformers (some->> entries
                                               (mapcat (fn [[k _ s]] (if-let [t (-transformer s transformer context)] [k t])))
                                               (seq)
@@ -783,13 +783,22 @@
                              (mapcat #(-> % (children opts) (-parse-keys opts) :forms) schemas))))
                    (schema opts)))))))
 
-(defn map-key []
+(defn map-key [parent-schema]
   ^{:type ::schema}
   (reify Schema
     (-name [_] ::map-key)
     (-form [_] ::map-key)
     (-properties [_])
-    (-transformer [this transformer context] (-value-transformer transformer this context))))
+    (-transformer [this transformer context]
+      (let [transformer-opts (-transformer-options transformer)
+            opt-key          (case context
+                               :encode :encoders
+                               :decode :decoders)
+            opts             (:opts transformer-opts)]
+        (if-let [->transformer (some-> transformer-opts
+                                       opt-key
+                                       ::map-key)]
+          (->transformer parent-schema opts))))))
 
 ;;
 ;; registries
diff --git a/test/malli/transform_test.cljc b/test/malli/transform_test.cljc
index 3b3788f4e..0ab19853e 100644
--- a/test/malli/transform_test.cljc
+++ b/test/malli/transform_test.cljc
@@ -198,8 +198,23 @@
 
 (deftest key-transformer
   (let [key-transformer (mt/key-transformer
-                          #(-> % name (str "_key") keyword)
-                          #(-> % name (str "_key")))]
+                         #(-> % name (str "_key") keyword)
+                         #(-> % name (str "_key")))
+
+        schema-aware-key-fn (fn [schema opts]
+                              (is (= [:x :y [:opt :z]]
+                                     (vec (map first (m/children schema)))))
+                              (is (nil? opts))
+                              #(name %))
+
+        schema-aware-key-transformer (mt/transformer
+                                      {:name ::custom
+                                       :encoders {::m/map-key schema-aware-key-fn}})]
+    (testing "schema-aware-key-fn"
+      (is (= {"x" 18 "y" "john" "a" "doe"}
+             (m/encode [:map [:x int?] [:y string?] [[:opt :z] boolean?]]
+                       {:x 18 :y "john" :a "doe"}
+                       schema-aware-key-transformer))))
     (testing "decode"
       (is (= {:x_key 18 :y_key "john" :a_key "doe"}
              (m/decode [:map [:x int?] [:y string?] [[:opt :z] boolean?]]