diff --git a/packages/oas-to-har/src/index.ts b/packages/oas-to-har/src/index.ts
index ecd2edd9..279f4bb1 100644
--- a/packages/oas-to-har/src/index.ts
+++ b/packages/oas-to-har/src/index.ts
@@ -222,11 +222,7 @@ export default function oasToHar(
   operationSchema?: Operation,
   values: DataForHAR = {},
   auth: AuthForHAR = {},
-  opts: oasToHarOptions = {
-    // If true, the operation URL will be rewritten and prefixed with https://try.readme.io/ in
-    // order to funnel requests through our CORS-friendly proxy.
-    proxyUrl: false,
-  },
+  opts: oasToHarOptions = { proxyUrl: '' },
 ) {
   let operation: Operation;
   if (!operationSchema || typeof operationSchema.getParameters !== 'function') {
@@ -287,7 +283,7 @@ export default function oasToHar(
 
   if (opts.proxyUrl) {
     if (oas.getExtension(PROXY_ENABLED, operation)) {
-      har.url = `https://try.readme.io/${har.url}`;
+      har.url = `${opts.proxyUrl}/${har.url}`;
     }
   }
 
diff --git a/packages/oas-to-har/src/lib/types.ts b/packages/oas-to-har/src/lib/types.ts
index b84f548b..63ad11ea 100644
--- a/packages/oas-to-har/src/lib/types.ts
+++ b/packages/oas-to-har/src/lib/types.ts
@@ -3,7 +3,10 @@ export type AuthForHAR = Record<string, number | string | { pass?: string; user?
 export { DataForHAR } from 'oas/types';
 
 export interface oasToHarOptions {
-  // If true, the operation URL will be rewritten and prefixed with https://try.readme.io/ in
-  // order to funnel requests through our CORS-friendly proxy.
-  proxyUrl: boolean;
+  /* the URL of a proxy to use. Requests will be preefixed with its value; for
+   * example if you use "https://try.readme.io", a request to
+   * "https://example.com/some/api" will be sent to
+   * "https://try.readme.io/https://example.com/some/api"
+   */
+  proxyUrl: string;
 }
diff --git a/packages/oas-to-har/test/index.test.ts b/packages/oas-to-har/test/index.test.ts
index caa383c4..d7aa2fcb 100644
--- a/packages/oas-to-har/test/index.test.ts
+++ b/packages/oas-to-har/test/index.test.ts
@@ -204,13 +204,19 @@ describe('oas-to-har', () => {
         });
       });
 
-      it('should not be prefixed with without option', () => {
+      it('should not be prefixed without proxyUrl', () => {
         const har = oasToHar(proxyOas, proxyOas.operation('/path', 'get'));
         expect(har.log.entries[0].request.url).toBe('https://example.com/path');
       });
 
-      it('should be prefixed with try.readme.io with option', () => {
-        const har = oasToHar(proxyOas, proxyOas.operation('/path', 'get'), {}, {}, { proxyUrl: true });
+      it('should be prefixed with proxyUrl', () => {
+        const har = oasToHar(
+          proxyOas,
+          proxyOas.operation('/path', 'get'),
+          {},
+          {},
+          { proxyUrl: 'https://try.readme.io' },
+        );
         expect(har.log.entries[0].request.url).toBe('https://try.readme.io/https://example.com/path');
       });
     });