diff --git a/src/main/clj/dda/c4k_common/yaml.clj b/src/main/clj/dda/c4k_common/yaml.clj
index d47d631..e5ba27c 100644
--- a/src/main/clj/dda/c4k_common/yaml.clj
+++ b/src/main/clj/dda/c4k_common/yaml.clj
@@ -4,20 +4,22 @@
    [clj-yaml.core :as yaml]
    [clojure.walk]
    [orchestra.core :refer [defn-spec]]
-   [orchestra.spec.test :as st]))
+   [dda.c4k-common.predicate :as cp]))
 
 
 
-(defn-spec cast-lazy-seq-to-vec vector?
-  [lazy-seq map?]
+(defn-spec resolve-lazy-sequences cp/map-or-seq?
+  [lazy-seq cp/map-or-seq?]
   (clojure.walk/postwalk #(if (instance? clojure.lang.LazySeq %)
                             (into [] %)
                             %) lazy-seq))
 
-(defn-spec from-string map? [input string?]
-  (cast-lazy-seq-to-vec (yaml/parse-string input)))
+(defn-spec from-string cp/map-or-seq? 
+  [input string?]
+  (resolve-lazy-sequences (yaml/parse-string input)))
 
-(defn-spec to-string string? [edn map?]
+(defn-spec to-string string?
+  [edn cp/map-or-seq?]
   (yaml/generate-string edn :dumper-options {:flow-style :block}))
 
 (defn dispatch-by-resource-name 
@@ -27,6 +29,4 @@
 (defmulti load-resource dispatch-by-resource-name)
 
 (defmethod load-resource :clj [resource-name]
-  (slurp (io/resource  resource-name)))
-
-(st/instrument)
\ No newline at end of file
+  (slurp (io/resource  resource-name)))
\ No newline at end of file
diff --git a/src/main/cljc/dda/c4k_common/common.cljc b/src/main/cljc/dda/c4k_common/common.cljc
index ee61e12..da9fc4d 100644
--- a/src/main/cljc/dda/c4k_common/common.cljc
+++ b/src/main/cljc/dda/c4k_common/common.cljc
@@ -2,7 +2,7 @@
   (:require
    [clojure.walk]))
 
-;; deprecated functions were moved to dda.c4k-common.prefixes
+;; deprecated functions were moved to dda.c4k-common.predicate
 (defn ^{:deprecated "0.1"} bash-env-string?
   [input]
   (and (string? input)
diff --git a/src/main/cljc/dda/c4k_common/postgres.cljc b/src/main/cljc/dda/c4k_common/postgres.cljc
index 9adbcd4..88491fa 100644
--- a/src/main/cljc/dda/c4k_common/postgres.cljc
+++ b/src/main/cljc/dda/c4k_common/postgres.cljc
@@ -4,7 +4,7 @@
    #?(:cljs [shadow.resource :as rc])
    [dda.c4k-common.yaml :as yaml]
    [dda.c4k-common.base64 :as b64]
-   [dda.c4k-common.prefixes :as cp]
+   [dda.c4k-common.predicate :as cp]
    [dda.c4k-common.common :as cm]))
 
 (defn postgres-size?
diff --git a/src/main/cljc/dda/c4k_common/prefixes.cljc b/src/main/cljc/dda/c4k_common/predicate.cljc
similarity index 70%
rename from src/main/cljc/dda/c4k_common/prefixes.cljc
rename to src/main/cljc/dda/c4k_common/predicate.cljc
index 1dd4b17..a5ffa2c 100644
--- a/src/main/cljc/dda/c4k_common/prefixes.cljc
+++ b/src/main/cljc/dda/c4k_common/predicate.cljc
@@ -1,4 +1,4 @@
-(ns dda.c4k-common.prefixes)
+(ns dda.c4k-common.predicate)
 
 (defn bash-env-string?
   [input]
@@ -12,4 +12,8 @@
 
 (defn letsencrypt-issuer?
   [input]
-  (contains? #{:prod :staging} input))
\ No newline at end of file
+  (contains? #{:prod :staging} input))
+
+(defn map-or-seq?
+  [input]
+  (or (map? input) (seq? input)))
\ No newline at end of file
diff --git a/src/main/cljs/dda/c4k_common/yaml.cljs b/src/main/cljs/dda/c4k_common/yaml.cljs
index e768dc3..b3f467a 100644
--- a/src/main/cljs/dda/c4k_common/yaml.cljs
+++ b/src/main/cljs/dda/c4k_common/yaml.cljs
@@ -1,17 +1,21 @@
 (ns dda.c4k-common.yaml
   (:require
    ["js-yaml" :as yaml]
-   [clojure.string :as st]))
+   [clojure.string :as st]
+   [orchestra.core :refer-macros [defn-spec]]
+   [dda.c4k-common.predicate :as cp]))
 
-(defn from-string [input]
+(defn-spec from-string cp/map-or-seq?
+  [input string?]
   (js->clj (yaml/load input)
            :keywordize-keys true))
 
-(defn to-string [edn]
+(defn-spec to-string string? 
+  [edn cp/map-or-seq?]
   (yaml/dump (clj->js  edn)))
 
-(defn dispatch-by-resource-name
-  [resource]
+(defn-spec dispatch-by-resource-name keyword?
+  [resource string?]
   (keyword (first (st/split resource #"/"))))
 
 (defmulti load-resource dispatch-by-resource-name)
diff --git a/src/test/clj/dda/c4k_common/yaml_test.clj b/src/test/clj/dda/c4k_common/yaml_test.clj
index 6a16d50..87be0ac 100644
--- a/src/test/clj/dda/c4k_common/yaml_test.clj
+++ b/src/test/clj/dda/c4k_common/yaml_test.clj
@@ -1,7 +1,8 @@
 (ns dda.c4k-common.yaml-test
   (:require
    [clojure.test :refer [deftest is are testing run-tests]]
-   [dda.c4k-common.yaml :as cut]))
+   [dda.c4k-common.yaml :as cut]
+   [orchestra.spec.test :as st]))
 
 (deftest should-dispatch-by-resource-name
   (is (= :clj
@@ -46,3 +47,5 @@
                 {:serviceName "another_keycloak"
                  :servicePort 8081}}]}}]}}
          (cut/from-string (cut/load-resource "test/ingress_test.yaml")))))
+
+(st/instrument)