diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
index 8f44817318..b6c5116943 100644
--- a/libavcodec/wmadec.c
+++ b/libavcodec/wmadec.c
@@ -715,7 +715,7 @@ static int wma_decode_block(WMADecodeContext *s)
 {
     int n, v, a, ch, code, bsize;
     int coef_nb_bits, total_gain, parse_exponents;
-    float window[BLOCK_MAX_SIZE * 2];
+    DECLARE_ALIGNED_16(float, window[BLOCK_MAX_SIZE * 2]);
 // XXX: FIXME!! there's a bug somewhere which makes this mandatory under altivec
 #ifdef HAVE_ALTIVEC
     volatile int nb_coefs[MAX_CHANNELS] __attribute__((aligned(16)));