diff --git a/examples/middle_amp.scri b/examples/middle_amp.scri
index f159c8e..a5928fd 100644
--- a/examples/middle_amp.scri
+++ b/examples/middle_amp.scri
@@ -1,3 +1,3 @@
 load :0;
-amp 3 1 10;
+amp 3 1 20;
 quicksave;
diff --git a/src/image.zig b/src/image.zig
index 491e994..1523133 100644
--- a/src/image.zig
+++ b/src/image.zig
@@ -190,19 +190,17 @@ pub const Image = struct {
 
         while (i <= end) : (i += buf.len) {
             std.debug.warn("i={}, buf.len={}, end={}\n", i, buf.len, end);
-            const excess = @intCast(i64, i + buf.len) - @intCast(i64, end);
+            sseek(self.sndfile, i);
+            sseek(out_file, i);
+
+            const bytes_until_end = end - i;
 
             var read_bytes: i64 = undefined;
             var view: []f32 = buf[0..buf.len];
 
-            if (excess > 0) {
-                std.debug.warn(
-                    "excess of {} bytes, reading {} instead\n",
-                    excess,
-                    @intCast(i64, buf.len) - excess,
-                );
-                read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @intCast(i64, buf.len) - excess);
-                view = buf[0..@intCast(usize, excess)];
+            if (bytes_until_end < buf.len) {
+                read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @intCast(i64, bytes_until_end));
+                view = buf[0..bytes_until_end];
             } else {
                 read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @intCast(i64, buf.len));
             }