diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80b2e5cf..ffac253d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+Version 99:
+
+* Log the value of LIB_DIR for doc builds (debug)
+
+--------------------------------------------------------------------------------
+
 Version 98:
 
 * basic_fields::key_compare is noexcept
diff --git a/doc/Jamfile b/doc/Jamfile
index 9c53db23..7cf0e700 100644
--- a/doc/Jamfile
+++ b/doc/Jamfile
@@ -85,6 +85,7 @@ if [ os.name ] = NT
     {
         SET LIB_DIR=$(2:B=:S=..)
         SET XML_OUTPUT=$(1:D)
+        echo "LIB_DIR=$(LIB_DIR)" > $(LIB_DIR)/doc/html/lib_dir.txt
         "$(.doxygen)" $(2)
     }
 }