diff --git a/libavcodec/x86/ac3dsp.asm b/libavcodec/x86/ac3dsp.asm
index ef59db2b3b..b4986ad50f 100644
--- a/libavcodec/x86/ac3dsp.asm
+++ b/libavcodec/x86/ac3dsp.asm
@@ -66,7 +66,7 @@ cglobal ac3_exponent_min, 3, 4, 2, exp, reuse_blks, expn, offset
 %define LOOP_ALIGN
 INIT_MMX mmx
 AC3_EXPONENT_MIN
-%if HAVE_MMXEXT
+%if HAVE_MMXEXT_EXTERNAL
 %define LOOP_ALIGN ALIGN 16
 INIT_MMX mmxext
 AC3_EXPONENT_MIN