diff --git a/configure.ac b/configure.ac
index 8b40c4e39..6ce3a78ff 100644
--- a/configure.ac
+++ b/configure.ac
@@ -440,6 +440,7 @@ RB_CHK_SYSHEADER([iphlpapi.h], [IPHLPAPI_H])
 
 dnl experimental
 RB_CHK_SYSHEADER([experimental/string_view], [EXPERIMENTAL_STRING_VIEW])
+RB_CHK_SYSHEADER([experimental/optional], [EXPERIMENTAL_OPTIONAL])
 
 
 dnl
diff --git a/include/ircd/stdinc.h b/include/ircd/stdinc.h
index be87d1d1b..3066d7cb0 100644
--- a/include/ircd/stdinc.h
+++ b/include/ircd/stdinc.h
@@ -93,7 +93,6 @@ extern "C" {
 #include <RB_INC_STRING
 #include <RB_INC_CSTRING
 #include <RB_INC_STRING_VIEW
-#include <RB_INC_EXPERIMENTAL_STRING_VIEW
 #include <RB_INC_LOCALE
 #include <RB_INC_CODECVT
 #include <RB_INC_MAP
@@ -117,6 +116,10 @@ extern "C" {
 #include <RB_INC_CONDITION_VARIABLE
 #include <RB_INC_RANDOM
 #include <RB_INC_BITSET
+#include <RB_INC_OPTIONAL
+
+#include <RB_INC_EXPERIMENTAL_STRING_VIEW
+#include <RB_INC_EXPERIMENTAL_OPTIONAL
 
 ///////////////////////////////////////////////////////////////////////////////
 //
@@ -142,6 +145,14 @@ namespace std
 }
 #endif
 
+// Experimental std::optional
+#if __cplusplus <= 20170519 //TODO: refine
+namespace std
+{
+	using experimental::optional;
+}
+#endif
+
 // OpenSSL
 // Additional forward declarations in the extern namespace are introduced
 // by ircd/openssl.h