diff --git a/implementations/javascript/package.json b/implementations/javascript/package.json
index e07d0a2..ea0f1c8 100644
--- a/implementations/javascript/package.json
+++ b/implementations/javascript/package.json
@@ -1,6 +1,6 @@
 {
   "name": "preserves",
-  "version": "0.5.1",
+  "version": "0.5.2",
   "description": "Experimental data serialization format",
   "homepage": "https://gitlab.com/preserves/preserves",
   "license": "Apache-2.0",
diff --git a/implementations/javascript/src/values.ts b/implementations/javascript/src/values.ts
index 24856bb..579aebd 100644
--- a/implementations/javascript/src/values.ts
+++ b/implementations/javascript/src/values.ts
@@ -94,6 +94,10 @@ export abstract class Float {
 
     static isSingle = (x: any): x is Single => Float.isFloat(x, 'Single');
     static isDouble = (x: any): x is Double => Float.isFloat(x, 'Double');
+
+    static unwrap(f: number | Float): number {
+        return typeof f === 'number' ? f : f.value;
+    }
 }
 
 export class Single extends Float implements Preservable<never> {