diff --git a/main.lua b/main.lua
index fe45186..de2bcf8 100644
--- a/main.lua
+++ b/main.lua
@@ -548,7 +548,7 @@ function updateWaveCanvas(waveview)
     local last = 70
     for i, v in ipairs(waveview) do
         local x = (i * step)
-        local y = (v + 1) * 70
+        local y = (-v + 1) * 70
 
         love.graphics.line(x - step, last, x, y)
         last = y
diff --git a/sfxr.lua b/sfxr.lua
index 1bd549c..a1cc40a 100644
--- a/sfxr.lua
+++ b/sfxr.lua
@@ -947,7 +947,7 @@ function sfxr.Sound:exportWAV(f, freq, bits)
         if bits == sfxr.BITS_16 then
             -- wrap around a bit
             if v >= 256^2 then v = 0 end
-            if v < 0 then v = 256^2 - 1 end
+            if v < 0 then v = 256^2 + v end
             w16(v)
         else
             f:write(string.char(v))