diff --git a/test/propeller/push/instructions/string_spec.clj b/test/propeller/push/instructions/string_spec.clj
index 07c9f48..0a52ecf 100644
--- a/test/propeller/push/instructions/string_spec.clj
+++ b/test/propeller/push/instructions/string_spec.clj
@@ -246,4 +246,19 @@
 
 (defspec last-spec 100
   (prop/for-all [str gen/string]
-                (check-last str)))
\ No newline at end of file
+                (check-last str)))
+
+
+;; string/length
+
+(defn check-length
+  [value]
+  (let [start-state (state/push-to-stack state/empty-state :string value)
+        end-state ((:string_length @core/instruction-table) start-state)
+        expected-result (count value)]
+    (= expected-result
+       (state/peek-stack end-state :integer))))
+
+(defspec length-spec 100
+  (prop/for-all [str gen/string]
+                (check-length str)))
\ No newline at end of file