diff --git a/src/stock/voice.cpp b/src/stock/voice.cpp
index 00da29bf2..4f4faac7f 100644
--- a/src/stock/voice.cpp
+++ b/src/stock/voice.cpp
@@ -107,11 +107,11 @@ void t_voice::voice_process(void)
         VoiceSerial += 260;
       }
       VoiceTimer = 16;
-      if ((VoiceSerial & 0x01F0) == 0xF0) { // Looking for F0-F7 or FF
-        if (VoiceSerial == 0xFF) {
+      if (VoiceSerial == 0xFF) { // Looking for FF
           VoiceShift = 1;
           return;
         }
+      if ((VoiceSerial & 0x01F8) == 0xF0) { // Looking for F0-F7
         VoiceSerial |= 0xFF00;
         VoiceTimer = 40;
       }
diff --git a/src/translations/cz.h b/src/translations/cz.h
index d2e0bc5b2..68117aa2c 100644
--- a/src/translations/cz.h
+++ b/src/translations/cz.h
@@ -285,8 +285,8 @@
 #define TR_MULTPX       "Mat.Operace"
 #define TR_DELAYDOWN    "Zpo\217d\203n\204 Vyp"
 #define TR_DELAYUP      "Zpo\217d\203n\204 Zap"
-#define TR_SLOWDOWN     "Zpomal. Vyp"
-#define TR_SLOWUP       "Zpomal. Zap"
+#define TR_SLOWDOWN     "Zpomalen\204(-)"
+#define TR_SLOWUP       "Zpomalen\204(+)"
 #define TR_MIXER        "MIXER"
 #define TR_CV           "CV"
 #define TR_ACHANNEL     "A\002Kan\200l"