diff --git a/src/acconfig.h b/src/acconfig.h
index f0864d62a4ee2105389cc224afa59e8537c9f6f0..6e8df0866c268f05579cca15f7e83d842e08aba3 100644
--- a/src/acconfig.h
+++ b/src/acconfig.h
@@ -68,6 +68,9 @@
 /* With this, dmalloc will report leaks made by malloc(3) calls */
 #undef REPORT_ENCAPSULATED_MALLOC
 
+/* Define this to enable atomic svalues */
+#undef ATOMIC_SVALUE
+
 /* Define this to enable the internal Pike security system */
 #undef PIKE_SECURITY
 
diff --git a/src/configure.in b/src/configure.in
index de90ac41bc35115b3dd92fa2b41246507001f0be..1e656f7d92f91ffe68e898e4a45ac18493bcb654 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -1622,6 +1622,13 @@ MY_AC_ARG_WITH(oob, MY_DESCR([--without-oob],
 MY_AC_ARG_WITH(compiler-trace, MY_DESCR([--with-compiler-trace],
 					[enable tracing of the compiler]),
 	       [AC_DEFINE(YYDEBUG)])
+MY_AC_ARG_WITH(atomic-svalue,
+               MY_DESCR([--with-atomic-svalue],
+	                [change the svalue representation to one])
+MY_DESCR([],[supporting atomic changes (EXPERIMENTAL)]),
+               [ AC_DEFINE(ATOMIC_SVALUE)
+	         PIKE_MSG_WARN([Atomic svalues enabled.])
+	       ])
 AC_ARG_WITH(security, MY_DESCR([--with-security],
 			       [enable internal pike security system]),
 	    [AC_DEFINE(PIKE_SECURITY)])