diff --git a/src/application/JavaScriptFileUrlPaths.test.ts b/src/application/JavaScriptFileUrlPaths.test.ts
new file mode 100644
index 0000000000..0a4a5cdd87
--- /dev/null
+++ b/src/application/JavaScriptFileUrlPaths.test.ts
@@ -0,0 +1,95 @@
+import { mkdir, readFile, writeFile } from "node:fs/promises";
+import { dirname, join, relative } from "node:path";
+import { fileURLToPath, pathToFileURL } from "node:url";
+
+import { parseExpression } from "@babel/parser";
+import { describe, expect, it } from "vitest";
+
+import { createTestTempDirectory } from "../../tests/fixtures/temporaryDirectory.js";
+import { javascriptApplicationAnalysisResultSchema } from "../domain/javascriptApplicationAnalysis.js";
+import { staticPath } from "../domain/javascriptStaticAnalysisHelpers.js";
+import { analyzeJavaScriptApplication } from "./JavaScriptApplicationService.js";
+
+const urlCases = [
+  ["./preload%20name.cjs", "preload name.cjs", "main.mjs"],
+  ["./pr%C3%A9load.cjs", "préload.cjs", "main.mjs"],
+  ["./preload%3F%23.cjs", "preload?#.cjs", "main.mjs"],
+  ["./preload.cjs?cache=1#v2", "preload.cjs", "main.mjs"],
+  ["../preload.cjs?cache=1", "preload.cjs", "src/main.mjs"],
+  ["./sub/../preload.cjs", "preload.cjs", "main.mjs"],
+  ["./preload.cjs", "preload.cjs", "main.mjs"],
+] as const;
+
+const unknownExpressions = [
+  'fileURLToPath(new URL("./invalid%.cjs", import.meta.url))',
+  'fileURLToPath(new URL("./preload%2fname.cjs", import.meta.url))',
+  'fileURLToPath(new URL("./preload%5cname.cjs", import.meta.url))',
+  'fileURLToPath(new URL("./%2e/preload.cjs", import.meta.url))',
+  'fileURLToPath(new URL("https://example.test/preload.cjs", import.meta.url))',
+  'fileURLToPath(new URL("//example.test/preload.cjs", import.meta.url))',
+  'fileURLToPath(new URL("#fragment", import.meta.url))',
+  'fileURLToPath(new URL("?cache=1", import.meta.url))',
+  'fileURLToPath(new URL("./preload.cjs", runtimeBase))',
+  "fileURLToPath(new URL(runtimePath, import.meta.url))",
+  'convertFileURLToPath(new URL("./preload.cjs", import.meta.url))',
+];
+
+describe("source-relative file URL paths", () => {
+  it.each(urlCases)(
+    "resolves %s to the file read by Node",
+    async (reference, target, sourcePath) => {
+      const root = await createTestTempDirectory("rea-file-url-path-");
+      const sourceFile = join(root, sourcePath);
+      await mkdir(dirname(sourceFile), { recursive: true });
+      await writeFile(join(root, target), 'module.exports = "real preload";\n');
+      if (reference.includes("%") && sourcePath === "main.mjs")
+        await writeFile(
+          join(root, reference),
+          'module.exports = "encoded-name decoy";\n',
+        );
+      const nativePath = fileURLToPath(
+        new URL(reference, pathToFileURL(sourceFile)),
+      );
+      expect(relative(root, nativePath)).toBe(target);
+      expect(await readFile(nativePath, "utf8")).toContain("real preload");
+      await writeFile(
+        sourceFile,
+        `import { fileURLToPath } from "node:url";\nnew BrowserWindow({ webPreferences: { preload: fileURLToPath(new URL(${JSON.stringify(reference)}, import.meta.url)) } });\n`,
+      );
+
+      const result = await analyzeJavaScriptApplication({
+        input_path: root,
+        format: "directory",
+      });
+      expect(result.ok).toBe(true);
+      if (!result.ok) throw result.error;
+      const { graph } = javascriptApplicationAnalysisResultSchema.parse(
+        result.value.normalized_result,
+      );
+      const preloads = graph.nodes.filter(
+        ({ kind }) => kind === "electron-preload",
+      );
+      expect(preloads).toHaveLength(1);
+      expect(preloads[0]?.observations).not.toHaveLength(0);
+      for (const observation of preloads[0]?.observations ?? [])
+        expect(observation.properties).toMatchObject({
+          resolved_path: target,
+          resolution_status: "resolved",
+          resolution_context: "filesystem-expression",
+        });
+    },
+  );
+
+  it.each(unknownExpressions)("leaves unsupported %s unknown", (expression) => {
+    expect(
+      staticPath(parseExpression(expression, { sourceType: "module" })),
+    ).toBeUndefined();
+  });
+
+  it("does not URL-decode literal filesystem punctuation", () => {
+    const expression = 'path.join(__dirname, "preload%20?#.cjs")';
+    expect(
+      staticPath(parseExpression(expression, { sourceType: "module" })),
+    ).toBe("preload%20?#.cjs");
+  });
+});
diff --git a/src/domain/javascriptStaticAnalysisHelpers.ts b/src/domain/javascriptStaticAnalysisHelpers.ts
index 1f1c3a9590..a1353690ae 100644
--- a/src/domain/javascriptStaticAnalysisHelpers.ts
+++ b/src/domain/javascriptStaticAnalysisHelpers.ts
@@ -1,5 +1,6 @@
 import { createHash } from "node:crypto";
 import { posix } from "node:path";
+import { fileURLToPath } from "node:url";
 
 import * as t from "@babel/types";
 
@@ -184,8 +185,7 @@ const staticCallPath = (
       ? stringValue(node.arguments[0])
       : undefined;
   if (name === "fileURLToPath" || name.endsWith(".fileURLToPath")) {
-    const argument = argumentNode(node.arguments[0]);
-    return argument === undefined ? undefined : staticPathAt(argument);
+    return staticFileUrlPath(argumentNode(node.arguments[0]));
   }
   if (
     (name === "dirname" || name.endsWith(".dirname")) &&
@@ -207,6 +207,59 @@ const staticCallPath = (
   return parts.length === 0 ? undefined : posix.join(...parts);
 };
 
+const staticFileUrlPath = (
+  argument: t.Node | undefined,
+): string | undefined => {
+  if (argument === undefined) return undefined;
+  return isSourceFileUrl(argument)
+    ? sourceRelativeFileUrlPath(argument)
+    : staticPathAt(argument);
+};
+
+/** Project a known source-relative URL through the actual file URL decoder. */
+const sourceRelativeFileUrlPath = (node: t.Node): string | undefined => {
+  if (!isSourceFileUrl(node)) return undefined;
+  const value = stringValue(node.arguments[0]);
+  if (
+    value === undefined ||
+    (value.split(/[?#]/u, 1)[0] ?? "") === "" ||
+    value !== value.trim() ||
+    value.includes("\\") ||
+    [...value].some((character) => character.charCodeAt(0) < 32) ||
+    /^[a-z][a-z0-9+.-]*:/iu.test(value) ||
+    value.startsWith("//") ||
+    /%(?:2e|2f|5c)/iu.test(value.split(/[?#]/u, 1)[0] ?? "")
+  )
+    return undefined;
+  // A sufficiently deep inert anchor preserves any leading parent segments
+  // without using this host's cwd or inventing the application's directory.
+  const directory = `/${"source/".repeat(value.split("/").length + 1)}`;
+  try {
+    const resolved = new URL(value, `file://${directory}entry.js`);
+    const path = fileURLToPath(resolved, { windows: false });
+    if (value.startsWith("/")) return path;
+    const relative = posix.relative(directory, path) || ".";
+    // Keep the established explicit source-directory observation spelling.
+    return value.startsWith("./") &&
+      relative !== "." &&
+      !relative.startsWith("../")
+      ? `./${relative}`
+      : relative;
+  } catch (cause: unknown) {
+    // Malformed escapes and non-file URL forms remain unknown.
+    void cause;
+    return undefined;
+  }
+};
+
+const isSourceFileUrl = (
+  node: t.Node,
+): node is t.CallExpression | t.NewExpression =>
+  (t.isCallExpression(node) || t.isNewExpression(node)) &&
+  (calleeName(node.callee) === "URL" ||
+    calleeName(node.callee).endsWith(".URL")) &&
+  isFileIdentity(argumentNode(node.arguments[1]));
+
 const staticResolvedPath = (
   node: t.CallExpression | t.NewExpression,
 ): string | undefined => {