diff --git a/configure.ac b/configure.ac
index 4f00f6636..d0bc0ed85 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1047,6 +1047,7 @@ AC_HELP_STRING([--with-sodium-libs=[[[DIR]]]], [Path to sodium library directory
 PKG_CHECK_MODULES(SODIUM, libsodium,
 [
 	have_sodium="yes"
+	AC_DEFINE([HAVE_SODIUM], [1], [Have libsodium])
 ], [
 	have_sodium="no"
 	AC_MSG_ERROR([libsodium is required but not found. Try apt-get install libsodium-dev])
diff --git a/include/ircd/buffer/buffer.h b/include/ircd/buffer/buffer.h
index f312625f7..223704f32 100644
--- a/include/ircd/buffer/buffer.h
+++ b/include/ircd/buffer/buffer.h
@@ -215,7 +215,7 @@ ircd::buffer::operator<<(std::ostream &s, const buffer<it> &buffer)
 
 // We use the sodium_memzero() from libsodium in ircd/sodium.cc if available
 // to ensure cross-platform guarantees the zero'ing doesn't get optimized away.
-#ifndef HAVE_SODIUM_H
+#ifndef HAVE_SODIUM
 inline size_t
 __attribute__((always_inline))
 ircd::buffer::zero(const mutable_buffer &buf)