diff --git a/nanovna.h b/nanovna.h
index 6b3ea05..6bafbc7 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -18,7 +18,7 @@
  */
 #include "ch.h"
 
-//#ifdef TINYSA_F303
+#ifdef TINYSA_F303
 #include "adc_F303.h"
 #ifdef TINYSA_F072
 #error "Remove comment for #ifdef TINYSA_F303"
@@ -27,7 +27,7 @@
 #define TINYSA4
 #endif
 #define TINYSA4_PROTO
-//#endif
+#endif
 
 #ifdef TINYSA_F072
 #ifdef TINYSA_F303
diff --git a/sa_core.c b/sa_core.c
index 5f79b10..cee5538 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -3963,11 +3963,13 @@ static bool sweep(bool break_on_operation)
         }
       }        // end of peak finding
     }
+#ifdef TINYSA4
     if (setting.average == AV_DECONV && setting.frequency_step != 0) {
       for (int i = sweep_points - 1 -  d_half_width*2; i>0; i--) {
         actual_t[i+d_half_width] = actual_t[i];
       }
     }
+#endif
   }