diff --git a/src/core/operations/GenerateHOTP.mjs b/src/core/operations/GenerateHOTP.mjs
index 75f5329f..c506dbd1 100644
--- a/src/core/operations/GenerateHOTP.mjs
+++ b/src/core/operations/GenerateHOTP.mjs
@@ -27,17 +27,23 @@ class GenerateHOTP extends Operation {
             {
                 "name": "Name",
                 "type": "string",
-                "value": ""
+                "value": "Account",
+                "allowEmpty": false
             },
             {
                 "name": "Code length",
                 "type": "number",
-                "value": 6
+                "value": 6,
+                "min": 6,
+                "max": 8,
+                "integer": true
             },
             {
                 "name": "Counter",
                 "type": "number",
-                "value": 0
+                "value": 0,
+                "min": 0,
+                "integer": true
             }
         ];
     }
@@ -47,7 +53,9 @@ class GenerateHOTP extends Operation {
      */
     run(input, args) {
         const secretStr = new TextDecoder("utf-8").decode(input).trim();
-        const secret = secretStr ? secretStr.toUpperCase().replace(/\s+/g, "") : "";
+        const secret = secretStr ?
+            OTPAuth.Secret.fromBase32(secretStr.toUpperCase().replace(/\s+/g, "")) :
+            new OTPAuth.Secret();
 
         const hotp = new OTPAuth.HOTP({
             issuer: "",
@@ -55,7 +63,7 @@ class GenerateHOTP extends Operation {
             algorithm: "SHA1",
             digits: args[1],
             counter: args[2],
-            secret: OTPAuth.Secret.fromBase32(secret)
+            secret
         });
 
         const uri = hotp.toString();
diff --git a/tests/node/tests/operations.mjs b/tests/node/tests/operations.mjs
index 6cf85718..4dd95246 100644
--- a/tests/node/tests/operations.mjs
+++ b/tests/node/tests/operations.mjs
@@ -605,8 +605,9 @@ Top Drawer`, {
 
     it("Generate HOTP", () => {
         const result = chef.generateHOTP("JBSWY3DPEHPK3PXP", {
+            name: "Account",
         });
-        const expected = `URI: otpauth://hotp/?secret=JBSWY3DPEHPK3PXP&algorithm=SHA1&digits=6&counter=0
+        const expected = `URI: otpauth://hotp/Account?secret=JBSWY3DPEHPK3PXP&algorithm=SHA1&digits=6&counter=0
 
 Password: 282760`;
         assert.strictEqual(result.toString(), expected);
diff --git a/tests/operations/tests/OTP.mjs b/tests/operations/tests/OTP.mjs
index 6e9739e4..59ca9fec 100644
--- a/tests/operations/tests/OTP.mjs
+++ b/tests/operations/tests/OTP.mjs
@@ -12,11 +12,77 @@ TestRegister.addTests([
     {
         name: "Generate HOTP",
         input: "JBSWY3DPEHPK3PXP",
-        expectedOutput: `URI: otpauth://hotp/?secret=JBSWY3DPEHPK3PXP&algorithm=SHA1&digits=6&counter=0\n\nPassword: 282760`,
+        expectedOutput: `URI: otpauth://hotp/Account?secret=JBSWY3DPEHPK3PXP&algorithm=SHA1&digits=6&counter=0\n\nPassword: 282760`,
         recipeConfig: [
             {
                 op: "Generate HOTP",
-                args: ["", 6, 0], // [Name, Code length, Counter]
+                args: ["Account", 6, 0], // [Name, Code length, Counter]
+            },
+        ],
+    },
+    {
+        name: "Generate HOTP - empty name rejected",
+        input: "JBSWY3DPEHPK3PXP",
+        expectedOutput: "Name cannot be empty.",
+        recipeConfig: [
+            {
+                op: "Generate HOTP",
+                args: ["", 6, 0],
+            },
+        ],
+    },
+    {
+        name: "Generate HOTP - code length below minimum rejected",
+        input: "JBSWY3DPEHPK3PXP",
+        expectedOutput: "Code length must be greater than or equal to 6.",
+        recipeConfig: [
+            {
+                op: "Generate HOTP",
+                args: ["Account", -6, 0],
+            },
+        ],
+    },
+    {
+        name: "Generate HOTP - code length above maximum rejected",
+        input: "JBSWY3DPEHPK3PXP",
+        expectedOutput: "Code length must be less than or equal to 8.",
+        recipeConfig: [
+            {
+                op: "Generate HOTP",
+                args: ["Account", 9, 0],
+            },
+        ],
+    },
+    {
+        name: "Generate HOTP - non-integer code length rejected",
+        input: "JBSWY3DPEHPK3PXP",
+        expectedOutput: "Code length must be an integer.",
+        recipeConfig: [
+            {
+                op: "Generate HOTP",
+                args: ["Account", 6.5, 0],
+            },
+        ],
+    },
+    {
+        name: "Generate HOTP - negative counter rejected",
+        input: "JBSWY3DPEHPK3PXP",
+        expectedOutput: "Counter must be greater than or equal to 0.",
+        recipeConfig: [
+            {
+                op: "Generate HOTP",
+                args: ["Account", 6, -1],
+            },
+        ],
+    },
+    {
+        name: "Generate HOTP - special characters in name are URI-encoded",
+        input: "JBSWY3DPEHPK3PXP",
+        expectedOutput: `URI: otpauth://hotp/user%40example.com?secret=JBSWY3DPEHPK3PXP&algorithm=SHA1&digits=6&counter=0\n\nPassword: 282760`,
+        recipeConfig: [
+            {
+                op: "Generate HOTP",
+                args: ["user@example.com", 6, 0],
             },
         ],
     },