diff --git a/tools/voice.pl b/tools/voice.pl
index 22a98c1d3c..dbbebd1262 100755
--- a/tools/voice.pl
+++ b/tools/voice.pl
@@ -225,7 +225,7 @@ sub voicestring {
         }
         case "espeak" {
             # xxx: $tts_engine_opts isn't used
-            $cmd = "espeak $tts_engine_opts -w $output";
+            $cmd = "espeak $tts_engine_opts -w \"$output\"";
             print("> $cmd\n") if $verbose;
             open(ESPEAK, "| $cmd");
             print ESPEAK $string . "\n";