diff --git a/sfizz/OnePoleFilter.h b/sfizz/OnePoleFilter.h
index 14d080ac..d7d1aad6 100644
--- a/sfizz/OnePoleFilter.h
+++ b/sfizz/OnePoleFilter.h
@@ -89,6 +89,9 @@ public:
         while (in < sentinel) {
             setGain(*g);
             oneLowpass(in, out);
+            in++;
+            out++;
+            g++;
         }
         return size;
     }
@@ -103,6 +106,9 @@ public:
         while (in < sentinel) {
             setGain(*g);
             oneLowpass(in, out);
+            in++;
+            out++;
+            g++;
         }
         return size;
     }