diff --git a/wasm/src/jsval.rs b/wasm/src/jsval.rs
index 1fed2fae..17019983 100644
--- a/wasm/src/jsval.rs
+++ b/wasm/src/jsval.rs
@@ -1,5 +1,5 @@
 use js_sys::JSON::stringify;
-use js_sys::{Array, BigInt, Object, Reflect};
+use js_sys::{Array, BigInt, Object, Reflect, Uint8Array};
 use wasm_bindgen::JsCast;
 
 use num_bigint::ToBigInt;
@@ -190,6 +190,11 @@ pub fn sexp_from_js_object(sstart: Srcloc, v: &JsValue) -> Option<Rc<SExp>> {
                     .and_then(|o| Object::try_from(&o).cloned())
                     .and_then(|o| location(&o))
                     .unwrap_or_else(|| sstart.clone());
+                if Uint8Array::instanceof(v) {
+                    // Explicitly handle uint8array conversion.
+                    let as_uint8array = Uint8Array::unchecked_from_js(v.clone());
+                    return Some(Rc::new(SExp::Atom(loc, as_uint8array.to_vec())));
+                }
                 get_property(o, "pair")
                     .and_then(|p| {
                         let pa = Array::from(&p);
diff --git a/wasm/src/objects.rs b/wasm/src/objects.rs
index fa693240..2188ce31 100644
--- a/wasm/src/objects.rs
+++ b/wasm/src/objects.rs
@@ -281,21 +281,21 @@ interface ITuple {
 interface IProgram {
     toString(): string;
     as_pair(): ITuple;
-    listp(): bool;
-    nullp(): bool;
+    listp(): boolean;
+    nullp(): boolean;
     as_int(): number;
     as_bigint(): bigint;
-    as_bin(): [Uint8Array];
+    as_bin(): Uint8Array;
     first(): IProgram;
     rest(): IProgram;
     cons(p: IProgram): IProgram;
-    run(code: IProgram, env: IProgram): [number, IProgram];
+    run(env: IProgram): [number, IProgram];
     list_len(): number;
-    equal_to(other: IProgram): bool;
+    equal_to(other: IProgram): boolean;
     as_javascript(): any;
     curry(args: [IProgram]): IProgram;
-    sha256tree(): [Uint8Array];
-    uncurry_error(): [IProgram];
+    sha256tree(): Uint8Array;
+    uncurry_error(): [IProgram, Array<IProgram>];
     uncurry(): [IProgram, Array<IProgram>|null];
 }
 "#;
diff --git a/wasm/tests/clvm-tools-interface/package.json b/wasm/tests/clvm-tools-interface/package.json
index 3fc737a5..a63cc6cd 100644
--- a/wasm/tests/clvm-tools-interface/package.json
+++ b/wasm/tests/clvm-tools-interface/package.json
@@ -8,7 +8,7 @@
     "start": "webpack serve --config webpack.config.demo.js",
     "build": "webpack && tsc",
     "build:demo": "webpack --config webpack.config.demo.js",
-    "test": "jest",
+    "test": "tsc -p tstestconfig.json --noEmit && jest",
     "coverage": "npm run test -- --coverage",
     "prepare": "npm run build",
     "trypublish": "npm publish || true"
diff --git a/wasm/tests/clvm-tools-interface/src/lib/tests/index.test.ts b/wasm/tests/clvm-tools-interface/src/lib/tests/index.test.ts
index b8420fa8..96863fd6 100644
--- a/wasm/tests/clvm-tools-interface/src/lib/tests/index.test.ts
+++ b/wasm/tests/clvm-tools-interface/src/lib/tests/index.test.ts
@@ -1,10 +1,11 @@
-import type { Program, IProgram, ITuple } from '../../../../../pkg/clvm_tools_wasm.d.ts';
+import type { IProgram, ITuple } from '../../../../../pkg/clvm_tools_wasm.js';
+import type { G1Element } from 'bls-signatures';
 
 import * as fs from 'fs';
 import { resolve } from 'path';
 import * as assert from 'assert';
 import * as bls_loader from 'bls-signatures';
-const {h, t, Program} = require('../../../../../pkg/clvm_tools_wasm');
+const {h, t, Program} = require('../../../../../pkg/clvm_tools_wasm.js');
 
 it('Has BLS signatures support', async () => {
     const bls = await bls_loader.default();
@@ -18,6 +19,28 @@ it('Has the "h" function', async () => {
     assert.equal([0x21, 0x20, 0x30, 0x31].toString(), unhexed.toString());
 });
 
+it('Converts uint8arrays', async () => {
+    let ua = new Uint8Array(3);
+    ua[0] = 0x30;
+    ua[1] = 0x81;
+    ua[2] = 0xff;
+    let p = Program.to(ua);
+    assert.equal([0x30, 0x81, 0xff].toString(), ua.toString());
+});
+
+it('Converts uint8arrays from the "h" function', async () => {
+    let unhexed = h('8b5fd961cb1a826823c45a796b350d0d6ba2398829f249b1e535fd76f6d150b1');
+    let p = Program.to([unhexed]);
+    assert.equal("ffa08b5fd961cb1a826823c45a796b350d0d6ba2398829f249b1e535fd76f6d150b180", p.toString());
+});
+
+it('Converts a buffer', async () => {
+    let unhexed = h('8b5fd961cb1a826823c45a796b350d0d6ba2398829f249b1e535fd76f6d150b1');
+    let b = Buffer.from(unhexed);
+    let p = Program.to([b]);
+    assert.equal("ffa08b5fd961cb1a826823c45a796b350d0d6ba2398829f249b1e535fd76f6d150b180", p.toString());
+});
+
 it('Converts to string', async () => {
     const converted_sexp = Program.to([1, 2, 3]);
     assert.equal("ff01ff02ff0380", converted_sexp.toString());
@@ -64,7 +87,7 @@ it('Has as_int', async () => {
     try {
         /*const non_int_value =*/ Program.to([7,13]).as_int();
         assert.fail('was an int but should not be');
-    } catch (e) {
+    } catch (e: any) {
         assert.equal(e.toString(), "not a number");
     }
 });
@@ -75,7 +98,7 @@ it('Has as_bigint', async () => {
     try {
         /*const non_int_value =*/ Program.to([7,13]).as_bigint();
         assert.fail('');
-    } catch (e) {
+    } catch (e: any) {
         assert.equal(e.toString(), "not a number");
     }
 });
@@ -87,13 +110,13 @@ it('Has first and rest', async () => {
     try {
         Program.to([]).first();
         assert.fail("empty list had first");
-    } catch (e) {
+    } catch (e: any) {
         assert.equal(e.toString(), "not a cons");
     }
     try {
         Program.to([]).rest();
         assert.fail("empty list had rest");
-    } catch (e) {
+    } catch (e: any) {
         assert.equal(e.toString(), "not a cons");
     }
 });
@@ -116,7 +139,7 @@ it('Has the t function', async () => {
 
 it('Has as_bin', async () => {
     const test_data = Program.to([7,8,9,10]);
-    const as_bin = test_data.as_bin();
+    const as_bin: Uint8Array = test_data.as_bin();
     assert.equal([255,7,255,8,255,9,255,10,128].toString(), as_bin.toString());
 });
 
@@ -168,8 +191,8 @@ export class ChiaExample {
     constructor(MOD: IProgram) {
         this.MOD = MOD;
     }
-    public puzzle_for_synthetic_public_key(synthetic_public_key: G1Element): Program {
-        return this.MOD.curry(synthetic_public_key);
+    public puzzle_for_synthetic_public_key(synthetic_public_key: G1Element): IProgram {
+        return this.MOD.curry(Program.to(synthetic_public_key));
     }
 }
 
@@ -178,15 +201,16 @@ it('works as expected in context', async () => {
     const program_text = fs.readFileSync(resolve(__dirname, '../../../content/p2_delegated_puzzle_or_hidden_puzzle.clvm.hex'),'utf-8');
     const MOD: IProgram = Program.from_hex(program_text);
     const ce = new ChiaExample(MOD);
-    const sk = bls.AugSchemeMPL.key_gen([
+    const sk = bls.AugSchemeMPL.key_gen(new Uint8Array([
         0, 50, 6, 244, 24, 199, 1, 25, 52, 88, 192, 19, 18, 12, 89, 6, 220,
         18, 102, 58, 209, 82, 12, 62, 89, 110, 182, 9, 44, 20, 254, 22
-    ]);
+    ]));
     const pk = bls.AugSchemeMPL.sk_to_g1(sk);
     // pk bytes 86243290bbcbfd9ae75bdece7981965350208eb5e99b04d5cd24e955ada961f8c0a162dee740be7bdc6c3c0613ba2eb1
     // Expected puzzle hash = 30cdae3d54778db5eba21584c452cfb1a278136b2ec352ba44a52078efea7507
     const target_puzzle = ce.puzzle_for_synthetic_public_key(pk);
-    assert.equal(target_puzzle.sha256tree().toString(), h('30cdae3d54778db5eba21584c452cfb1a278136b2ec352ba44a52078efea7507').toString());
+    const shatree_result: Uint8Array = target_puzzle.sha256tree();
+    assert.equal(shatree_result.toString(), h('30cdae3d54778db5eba21584c452cfb1a278136b2ec352ba44a52078efea7507').toString());
 });
 
 const cat2_puzzle = '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';
@@ -195,8 +219,8 @@ const cat2_curried_program = 'ff02ffff01ff02ffff01ff02ffff03ff0bffff01ff02ffff03
 
 it('can uncurry an example program', async () => {
     const to_uncurry_text = fs.readFileSync(resolve(__dirname, '../../../content/test_cat2_program.hex'),'utf-8');
-    const program: IProgram = Program.from_hex(to_uncurry_text);
-    const uncurried: Array<IProgram> = program.uncurry_error();
+    const program = Program.from_hex(to_uncurry_text);
+    const uncurried = program.uncurry_error();
     assert.equal(uncurried.length, 2);
     assert.equal(uncurried[1].length, 3);
     assert.equal(uncurried[0].toString(), cat2_puzzle);
diff --git a/wasm/tests/clvm-tools-interface/tsconfig.json b/wasm/tests/clvm-tools-interface/tsconfig.json
index 9ea99e98..655a5b6d 100644
--- a/wasm/tests/clvm-tools-interface/tsconfig.json
+++ b/wasm/tests/clvm-tools-interface/tsconfig.json
@@ -12,6 +12,7 @@
       "suppressImplicitAnyIndexErrors": true,
       "lib": ["es2018", "dom"],
       "moduleResolution": "node",
+      "target": "es2020"
     },
     "include": ["src/lib"],
     "exclude": ["src/lib/**/tests"],
diff --git a/wasm/tests/clvm-tools-interface/tstestconfig.json b/wasm/tests/clvm-tools-interface/tstestconfig.json
new file mode 100644
index 00000000..b47c040d
--- /dev/null
+++ b/wasm/tests/clvm-tools-interface/tstestconfig.json
@@ -0,0 +1,10 @@
+{
+    "extends": "./tsconfig.json",
+    "compilerOptions": {
+      "emitDeclarationOnly": false,
+      "noEmitOnError": true,
+      "strict": true,
+    },
+    "include": ["src/lib/**/tests"],
+    "exclude": []
+}