diff --git a/src/core/postscript/js_evaluator.js b/src/core/postscript/js_evaluator.js
index ecef299cd..9d71c5380 100644
--- a/src/core/postscript/js_evaluator.js
+++ b/src/core/postscript/js_evaluator.js
@@ -795,9 +795,15 @@ class PSStackBasedInterpreter {
  * @param {number[]} range   – flat [min0,max0, …]
  * @returns {Function}  – `(src, srcOffset, dest, destOffset) => void`
  */
-function buildPostScriptJsFunction(source, domain, range) {
+function buildPostScriptJsFunction(
+  source,
+  domain,
+  range,
+  forceInterpreter = false
+) {
   const program = parsePostScriptFunction(source);
-  const ir = new PsJsCompiler(domain, range).compile(program);
+  const ir =
+    !forceInterpreter && new PsJsCompiler(domain, range).compile(program);
   if (ir) {
     return (src, srcOffset, dest, destOffset) => {
       PsJsCompiler.execute(ir, src, srcOffset, dest, destOffset);
@@ -807,14 +813,4 @@ function buildPostScriptJsFunction(source, domain, range) {
   return PSStackBasedInterpreter.build(program, domain, range);
 }
 
-/**
- * @param {import("./ast.js").PsProgram} program
- * @param {number[]} domain  – flat [min0,max0, …]
- * @param {number[]} range   – flat [min0,max0, …]
- * @returns {Function}  – `(src, srcOffset, dest, destOffset) => void`
- */
-function buildPostScriptProgramFunction(program, domain, range) {
-  return PSStackBasedInterpreter.build(program, domain, range);
-}
-
-export { buildPostScriptJsFunction, buildPostScriptProgramFunction };
+export { buildPostScriptJsFunction };
diff --git a/test/unit/postscript_spec.js b/test/unit/postscript_spec.js
index 5ad7d69e9..cdfdcc0b5 100644
--- a/test/unit/postscript_spec.js
+++ b/test/unit/postscript_spec.js
@@ -13,10 +13,6 @@
  * limitations under the License.
  */
 
-import {
-  buildPostScriptJsFunction,
-  buildPostScriptProgramFunction,
-} from "../../src/core/postscript/js_evaluator.js";
 import {
   buildPostScriptWasmFunction,
   compilePostScriptToWasm,
@@ -39,6 +35,7 @@ import {
   PsTernaryNode,
   PsUnaryNode,
 } from "../../src/core/postscript/ast.js";
+import { buildPostScriptJsFunction } from "../../src/core/postscript/js_evaluator.js";
 
 // Precision argument for toBeCloseTo() in trigonometric tests.
 const TRIGONOMETRY_EPS = 1e-10;
@@ -209,10 +206,11 @@ describe("PostScript Type 4 lexer, parser, and Wasm compiler", function () {
       // direct program interpreter otherwise.
       const jsFn = buildPostScriptJsFunction(src, domain, range);
       // Direct interpreter: always available, never uses PSStackToTree.
-      const interpFn = buildPostScriptProgramFunction(
-        parsePostScriptFunction(src),
+      const interpFn = buildPostScriptJsFunction(
+        src,
         domain,
-        range
+        range,
+        /* forceInterpreter = */ true
       );
 
       if (!wasmFn) {