diff --git a/src/h/config.h.in b/src/h/config.h.in
index e6f555b88..ddcb9b825 100644
--- a/src/h/config.h.in
+++ b/src/h/config.h.in
@@ -429,7 +429,9 @@ typedef unsigned @CL_FIXNUM_TYPE@ cl_hashkey;
 #   ifdef HAVE_COPYSIGN
 #    define signbit(x) (copysign(1.0,(x)) < 0)
 #   else 
-#    error "When using signed zeros we need also signbit() or copysign()"
+     /* Fall back to no signed zero */
+#    undef ECL_SIGNED_ZERO
+#    define signbit(x) ((x) < 0)
 #   endif
 #  endif
 # endif