diff --git a/configure.ac b/configure.ac
index ffe754c3..f2cb6ddf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -398,7 +398,13 @@ AS_IF([test "x$EMSCRIPTEN" = "x" -a "$host_os" != "pnacl"], [
 #endif
 #pragma GCC target("avx2")
 #include <immintrin.h>
-]], [[ __m256i x = _mm256_abs_epi8(_mm256_setzero_si256()); ]])],
+]], [[
+// the code below is intentionally crafted to make sure the compiler
+// can't optimize the AVX2 instructions away.
+__m256 x = _mm256_set1_ps(3.14);
+__m256 y = _mm256_permutevar8x32_ps(x, _mm256_set1_epi32(42));
+return _mm256_movemask_ps(_mm256_cmp_ps(x, y, _CMP_NEQ_OQ));
+]])],
     [AC_MSG_RESULT(yes)
      AC_DEFINE([HAVE_AVX2INTRIN_H], [1], [AVX2 is available])
      AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS_AVX2="-mavx2"])