diff --git a/make-pdf/src/pdftotext.ts b/make-pdf/src/pdftotext.ts
index 5cdb51e81..df6d05335 100644
--- a/make-pdf/src/pdftotext.ts
+++ b/make-pdf/src/pdftotext.ts
@@ -26,7 +26,7 @@
  * Only the CI gate and unit tests invoke pdftotext.
  */
 
-import { execFileSync } from "node:child_process";
+import { execFileSync, spawnSync } from "node:child_process";
 import * as fs from "node:fs";
 import * as os from "node:os";
 import * as path from "node:path";
@@ -154,19 +154,25 @@ function isExecutable(p: string): boolean {
 function describeBinary(bin: string): PdftotextInfo {
   let version = "unknown";
   let flavor: PdftotextInfo["flavor"] = "unknown";
-  try {
-    // pdftotext -v writes to stderr and exits 0 on poppler, 99 on some xpdf builds.
-    const result = execFileSync(bin, ["-v"], {
-      encoding: "utf8",
-      stdio: ["ignore", "pipe", "pipe"],
-    });
-    version = (result || "").trim().split("\n")[0] || "unknown";
-  } catch (err: any) {
-    // Many pdftotext builds exit non-zero on -v but still write to stderr.
-    const stderr = err?.stderr?.toString?.() ?? "";
-    version = stderr.trim().split("\n")[0] || "unknown";
-  }
-  const v = version.toLowerCase();
+
+  // spawnSync, not execFileSync: poppler writes -v output to STDERR and exits 0,
+  // so execFileSync neither returns it (it returns stdout, which is empty) nor
+  // throws (which is what made the stderr fallback below reachable). The result
+  // was version="unknown" flavor="unknown" on every poppler install. spawnSync
+  // hands back both streams regardless of exit status, which also covers the
+  // xpdf builds that exit 99.
+  const res = spawnSync(bin, ["-v"], { encoding: "utf8" });
+  const raw = `${res.stdout ?? ""}\n${res.stderr ?? ""}`;
+
+  // The version banner is not reliably the first line once both streams are in
+  // play, so match it rather than taking line 0.
+  const lines = raw.split("\n").map(l => l.trim()).filter(Boolean);
+  version = lines.find(l => /pdftotext\s+version/i.test(l)) ?? lines[0] ?? "unknown";
+
+  // Flavor comes from the WHOLE banner, never the version line alone: poppler
+  // prints "pdftotext version 26.06.0" on line 1 and only identifies itself on
+  // line 2, "Copyright ... The Poppler Developers".
+  const v = raw.toLowerCase();
   if (v.includes("poppler")) flavor = "poppler";
   else if (v.includes("xpdf")) flavor = "xpdf";
   return { bin, version, flavor };
diff --git a/make-pdf/test/pdftotext.test.ts b/make-pdf/test/pdftotext.test.ts
index 4ab5c4fb7..871325e6b 100644
--- a/make-pdf/test/pdftotext.test.ts
+++ b/make-pdf/test/pdftotext.test.ts
@@ -8,6 +8,8 @@
 
 import { describe, expect, test } from "bun:test";
 
+import * as fs from "node:fs";
+import * as os from "node:os";
 import * as path from "node:path";
 import { normalize, copyPasteGate, findExecutable, resolvePdftotext, PdftotextUnavailableError } from "../src/pdftotext";
 
@@ -205,3 +207,96 @@ describe("resolvePdftotext (override resolution, v1.24-aligned)", () => {
     }
   });
 });
+
+// ─── Version + flavor probe (describeBinary via resolvePdftotext) ────
+//
+// Regression cover for the probe returning version="unknown" flavor="unknown"
+// on every poppler install. Two independent causes, both exercised here:
+//
+//   1. poppler writes its -v banner to STDERR and exits 0. The old code used
+//      execFileSync, which returns stdout (empty) and does not throw on a zero
+//      exit, so the stderr fallback in the catch block was unreachable.
+//   2. flavor was matched against the first line only. poppler prints
+//      "pdftotext version X" on line 1 and identifies itself on line 2
+//      ("Copyright ... The Poppler Developers"), so even a working stderr read
+//      yielded flavor="unknown".
+//
+// Real pdftotext binaries cannot be assumed present in CI, so these use shell
+// shims that reproduce each vendor's exact banner, stream and exit status.
+
+describe("describeBinary (version + flavor probe)", () => {
+  const shimDir = fs.mkdtempSync(path.join(os.tmpdir(), "pdftotext-shim-"));
+
+  function shim(name: string, body: string): string {
+    if (process.platform === "win32") return "";
+    const p = path.join(shimDir, name);
+    fs.writeFileSync(p, `#!/bin/sh\n${body}\n`, { mode: 0o755 });
+    return p;
+  }
+
+  // poppler: banner on stderr, exit 0, vendor named on line 2.
+  const popplerShim = shim(
+    "poppler-pdftotext",
+    [
+      'if [ "$1" = "-v" ]; then',
+      '  echo "pdftotext version 26.06.0" >&2',
+      '  echo "Copyright 2005-2026 The Poppler Developers - http://poppler.freedesktop.org" >&2',
+      '  echo "Copyright 1996-2011, 2022 Glyph & Cog, LLC" >&2',
+      "  exit 0",
+      "fi",
+      "exit 0",
+    ].join("\n"),
+  );
+
+  // xpdf: banner on stderr, non-zero exit, vendor named on line 1.
+  const xpdfShim = shim(
+    "xpdf-pdftotext",
+    [
+      'if [ "$1" = "-v" ]; then',
+      '  echo "pdftotext version 4.05 [xpdf]" >&2',
+      '  echo "Copyright 1996-2024 Glyph & Cog, LLC" >&2',
+      "  exit 99",
+      "fi",
+      "exit 0",
+    ].join("\n"),
+  );
+
+  test.skipIf(process.platform === "win32")(
+    "reads a poppler banner from stderr on a zero exit",
+    () => {
+      const info = withEnv({ GSTACK_PDFTOTEXT_BIN: popplerShim }, () => resolvePdftotext());
+      expect(info.version).toBe("pdftotext version 26.06.0");
+      expect(info.flavor).toBe("poppler");
+    },
+  );
+
+  test.skipIf(process.platform === "win32")(
+    "identifies poppler from the copyright line, not the version line",
+    () => {
+      const info = withEnv({ GSTACK_PDFTOTEXT_BIN: popplerShim }, () => resolvePdftotext());
+      // The line carrying the version does NOT contain the vendor name, which is
+      // exactly why a line-0-only match reported "unknown".
+      expect(info.version.toLowerCase()).not.toContain("poppler");
+      expect(info.flavor).toBe("poppler");
+    },
+  );
+
+  test.skipIf(process.platform === "win32")(
+    "reads an xpdf banner from stderr on a non-zero exit",
+    () => {
+      const info = withEnv({ GSTACK_PDFTOTEXT_BIN: xpdfShim }, () => resolvePdftotext());
+      expect(info.version).toBe("pdftotext version 4.05 [xpdf]");
+      expect(info.flavor).toBe("xpdf");
+    },
+  );
+
+  test.skipIf(process.platform === "win32")(
+    "falls back to unknown when the binary emits no banner",
+    () => {
+      const silent = shim("silent-pdftotext", "exit 0");
+      const info = withEnv({ GSTACK_PDFTOTEXT_BIN: silent }, () => resolvePdftotext());
+      expect(info.version).toBe("unknown");
+      expect(info.flavor).toBe("unknown");
+    },
+  );
+});