diff --git a/libavcodec/armv4l/dsputil_iwmmxt.c b/libavcodec/armv4l/dsputil_iwmmxt.c
index d7401e760f7f789a4a2c92e9991debb07915a58f..7536100ee739c79d2f671dbef597fa90795724e3 100644
--- a/libavcodec/armv4l/dsputil_iwmmxt.c
+++ b/libavcodec/armv4l/dsputil_iwmmxt.c
@@ -128,17 +128,13 @@ static void nop(uint8_t *block, const uint8_t *pixels, int line_size, int h)
     return;
 }
 
-int mm_flags; /* multimedia extension flags */
-
-int mm_support(void)
-{
-    return 0; /* TODO, implement proper detection */
-}
+/* A run time test is not simple. If this file is compiled in
+ * then we should install the functions
+ */
+int mm_flags = MM_IWMMXT; /* multimedia extension flags */
 
 void dsputil_init_iwmmxt(DSPContext* c, AVCodecContext *avctx)
 {
-    mm_flags = mm_support();
-
     if (avctx->dsp_mask) {
         if (avctx->dsp_mask & FF_MM_FORCE)
             mm_flags |= (avctx->dsp_mask & 0xffff);