diff --git a/configure.ac b/configure.ac
index f413a99e79994a2787d9da1c589ec510e4b29181..6113d080faaec1921757d16570b54d293ca02d3e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -284,7 +284,7 @@ AC_ARG_ENABLE([loop-unrolling],
      [Tell the compiler explicitly to unroll loops @<:@no/yes@:>@]
    )],
    [enable_loop_unrolling="$enableval"],
-   [enable_loop_unrolling="yes"]
+   [enable_loop_unrolling="$enable_opt"]
 )
 if test "$enable_loop_unrolling" = "yes"; then
     CFLAGS="$CFLAGS -funroll-loops"