diff --git a/addons/main/functions/fnc_doCallout.sqf b/addons/main/functions/fnc_doCallout.sqf
index e012d36f..f985f0d6 100644
--- a/addons/main/functions/fnc_doCallout.sqf
+++ b/addons/main/functions/fnc_doCallout.sqf
@@ -74,15 +74,18 @@ if (isNil "_cachedSounds") then {
     _cachedSounds = getArray (_protocolConfig >> _callout);
     private _deleted = false;
     {
-        private _sound = _x;
-        if (_sound == "") then {
-            _sound = objNull;
-            _deleted = true;
-        } else {
+        private _sound = toLowerANSI _x; // playSound3D is case-insensitive
+
+        // File extension must exist for playSound3D to work
+        if (_sound regexMatch ".+?\.(?:ogg|wss|wav|mp3)$/io") then {
             if (_sound select [0, 1] != "\") then {
                 _sound = (getArray (configFile >> "CfgVoice" >> _speaker >> "directories") select 0) + _sound;
             };
+        } else {
+            _sound = objNull;
+            _deleted = true;
         };
+
         _cachedSounds set [_forEachIndex, _sound];
     } forEach _cachedSounds;