Fix build error

a1q123456 · a1q123456 · commit 37dcc7d708fd · 2025-09-03T15:04:01.000+01:00
Signed-off-by: JCW &lt;a1q123456@users.noreply.github.com&gt;
diff --git a/include/xrpl/beast/utility/Journal.h b/include/xrpl/beast/utility/Journal.h
@@ -23,6 +23,7 @@
 #include <xrpl/beast/utility/instrumentation.h>
 
 #include <charconv>
+#include <mutex>
 #include <shared_mutex>
 #include <source_location>
 #include <sstream>
