diff --git a/plugin/voice.cpp b/plugin/voice.cpp
index 63da6e9..82151fb 100644
--- a/plugin/voice.cpp
+++ b/plugin/voice.cpp
@@ -41,7 +41,7 @@ void Voice::run(Synth &s, float *buffer, uint32_t samples) {
     // there's a resistor on the panel board to sprag the range
     float pw = s.ff4f / 32768.0f;
 
-    float sqr = 0.175;
+    float sqr = (s.patchRam.switch1 & 0x08) ? 0.175 : 0;
     float saw = (s.patchRam.switch1 & 0x10) ? 0.220 : 0;
     float sub = (s.patchRam.sub / 127.0f) * 0.275;