diff --git a/public/script.js b/public/script.js
index 490563f..e08c561 100644
--- a/public/script.js
+++ b/public/script.js
@@ -65,10 +65,11 @@ function handleFile(file) {
         updateSearchBar();
 
         if (defaultTo) {
-          const selector = defaultConverter
-            ? `.target[data-value="${defaultTo},${defaultConverter}"]`
-            : `.target[data-target="${defaultTo}"]`;
-          const targetBtn = document.querySelector(selector);
+          const targetBtn = Array.from(document.querySelectorAll(".target")).find((t) =>
+            defaultConverter
+              ? t.dataset.target === defaultTo && t.dataset.converter === defaultConverter
+              : t.dataset.target === defaultTo,
+          );
           if (targetBtn) {
             const convertToEl = document.querySelector("select[name='convert_to']");
             const convertToInputEl = document.querySelector("input[name='convert_to_search']");
diff --git a/src/converters/ffmpeg.ts b/src/converters/ffmpeg.ts
index f0418f4..f9d2f63 100644
--- a/src/converters/ffmpeg.ts
+++ b/src/converters/ffmpeg.ts
@@ -710,8 +710,9 @@ export async function convert(
   }
 
   if (convertTo === "wav-3cx") {
-    // 3CX telephony preset: mono, 8 kHz, 16-bit PCM
-    extraArgs.push("-ac", "1", "-ar", "8000", "-sample_fmt", "s16");
+    // 3CX telephony preset: mono, 8 kHz, 16-bit PCM (pcm_s16le is explicit to
+    // avoid FFMPEG_OUTPUT_ARGS overriding the codec and breaking 3CX playback)
+    extraArgs.push("-ac", "1", "-ar", "8000", "-c:a", "pcm_s16le");
   }
 
   if (convertTo.split(".").length > 1) {