diff --git a/src/core/operations/SHA2.mjs b/src/core/operations/SHA2.mjs
index ecdc4cc5..b55b7c28 100644
--- a/src/core/operations/SHA2.mjs
+++ b/src/core/operations/SHA2.mjs
@@ -5,6 +5,7 @@
  */
 
 import Operation from "../Operation.mjs";
+import OperationError from "../errors/OperationError.mjs";
 import {runHash} from "../lib/Hash.mjs";
 
 /**
@@ -83,6 +84,11 @@ class SHA2 extends Operation {
      */
     run(input, args) {
         const size = args[0];
+
+        if (!this.args[0].value.some(option => option.name === size)) {
+            throw new OperationError("Invalid SHA2 size");
+        }
+
         const rounds = (size === "256" || size === "224") ? args[1] : args[2];
         return runHash("sha" + size, input, {rounds: rounds});
     }
diff --git a/tests/operations/tests/Hash.mjs b/tests/operations/tests/Hash.mjs
index ba502934..4363d956 100644
--- a/tests/operations/tests/Hash.mjs
+++ b/tests/operations/tests/Hash.mjs
@@ -140,6 +140,17 @@ TestRegister.addTests([
             }
         ]
     },
+    {
+        name: "SHA2: invalid size",
+        input: "hi",
+        expectedOutput: "Invalid SHA2 size",
+        recipeConfig: [
+            {
+                "op": "SHA2",
+                "args": ["", 64, 13]
+            }
+        ]
+    },
     {
         name: "SHA3 224",
         input: "Hello, World!",