diff --git a/nanovna.h b/nanovna.h
index 90d3ad3..122bd65 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -18,7 +18,7 @@
  */
 #include "ch.h"
 
-//#ifdef TINYSA_F303
+#ifdef TINYSA_F303
 #ifdef TINYSA_F072
 #error "Remove comment for #ifdef TINYSA_F303"
 #endif
@@ -26,7 +26,7 @@
 #define TINYSA4
 #endif
 #define TINYSA4_PROTO
-//#endif
+#endif
 
 #ifdef TINYSA_F072
 #ifdef TINYSA_F303