diff --git a/source/SoundTouch/mmx_optimized.cpp b/source/SoundTouch/mmx_optimized.cpp
index 2d95bfa..cb38d98 100644
--- a/source/SoundTouch/mmx_optimized.cpp
+++ b/source/SoundTouch/mmx_optimized.cpp
@@ -287,6 +287,7 @@ void TDStretchMMX::overlapStereo(short *output, const short *input) const
 
 FIRFilterMMX::FIRFilterMMX() : FIRFilter()
 {
+    filterCoeffsAlign = NULL;
     filterCoeffsUnalign = NULL;
 }