diff --git a/configure.ac b/configure.ac
index e3132364..ffe754c3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -401,7 +401,7 @@ AS_IF([test "x$EMSCRIPTEN" = "x" -a "$host_os" != "pnacl"], [
 ]], [[ __m256i x = _mm256_abs_epi8(_mm256_setzero_si256()); ]])],
     [AC_MSG_RESULT(yes)
      AC_DEFINE([HAVE_AVX2INTRIN_H], [1], [AVX2 is available])
-     AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS_AVX="-mavx2"])
+     AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS_AVX2="-mavx2"])
      AC_MSG_CHECKING(if _mm256_broadcastsi128_si256 is correctly defined)
      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #ifdef __native_client__