diff --git a/src/feature.h b/src/feature.h
index 4df73d1..2ae739a 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -593,6 +593,13 @@
 # define FEAT_SOUND_CANBERRA
 #endif
 
+/*
+ * libsodium - add cryptography support
+ */
+#if defined(HAVE_SODIUM) && defined(FEAT_BIG)
+# define FEAT_SODIUM
+#endif
+
 // There are two ways to use XPM.
 #if (defined(HAVE_XM_XPMP_H) && defined(FEAT_GUI_MOTIF)) \
 		|| defined(HAVE_X11_XPM_H)