diff --git a/wasm/src/jsval.rs b/wasm/src/jsval.rs
index 170199836..1bb6b5cfc 100644
--- a/wasm/src/jsval.rs
+++ b/wasm/src/jsval.rs
@@ -10,7 +10,7 @@ use std::convert::TryFrom;
 use std::rc::Rc;
 use std::str::FromStr;
 
-use clvm_tools_rs::classic::clvm::__type_compatibility__::{Bytes, BytesFromType};
+use clvm_tools_rs::classic::clvm::__type_compatibility__::{bi_zero, Bytes, BytesFromType};
 use clvm_tools_rs::compiler::sexp::SExp;
 use clvm_tools_rs::compiler::srcloc::{Srcloc, Until};
 use clvm_tools_rs::util::Number;
@@ -168,7 +168,11 @@ pub fn sexp_from_js_object(sstart: Srcloc, v: &JsValue) -> Option<Rc<SExp>> {
     } else if let Some(fval) = v.as_f64() {
         (fval as i64)
             .to_bigint()
-            .map(|x| Rc::new(SExp::Integer(sstart.clone(), x)))
+            .map(|x| if x == bi_zero() {
+                Rc::new(SExp::Nil(sstart.clone()))
+            } else {
+                Rc::new(SExp::Integer(sstart.clone(), x))
+            })
     } else if let Some(g1_bytes) = detect_serializable(&sstart, v) {
         Some(g1_bytes)
     } else if let Ok(converted) = detect_convertible(v) {
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 96863fd66..d56d29e68 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
@@ -228,3 +228,22 @@ it('can uncurry an example program', async () => {
     assert.equal(uncurried[1][1].toString(), 'a06d95dae356e32a71db5ddcb42224754a02524c615c5fc35f568c2af04774e589');
     assert.equal(uncurried[1][2].toString(), cat2_curried_program);
 });
+
+// Thanks: fcoleman
+describe('Program', () => {
+    it('preserves the representation across js and hex representations', () => {
+        const puzzle1 = Program.to([0]);
+        const puzzleHash1 = Buffer.from(puzzle1.sha256tree()).toString('hex');
+
+        const puzzle2 = Program.from_hex(puzzle1.toString());
+        const puzzleHash2 = Buffer.from(puzzle2.sha256tree()).toString('hex');
+
+        const puzzle3 = Program.from_hex('ff8080');
+        const puzzleHash3 = Buffer.from(puzzle3.sha256tree()).toString('hex');
+
+        expect(puzzle1.toString()).toEqual(puzzle2.toString());
+        expect(puzzle1.toString()).toEqual(puzzle3.toString());
+        expect(puzzleHash1).toEqual(puzzleHash2);
+        expect(puzzleHash1).toEqual(puzzleHash3);
+    });
+})