diff --git a/debian/changelog b/debian/changelog
index 084eb484..b1340bfe 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -9,6 +9,8 @@ llvm-toolchain-9 (1:9.0.1~+rc2-1~exp2) UNRELEASED; urgency=medium
   * Rely on pre-initialized dpkg-architecture variables.
   * Bump debhelper from old 9 to 12.
   * Set debhelper-compat version in Build-Depends.
+  * Move transitional package libclang-cpp1-9 to oldlibs/optional per
+    policy 4.0.1.
 
  -- Sylvestre Ledru <sylvestre@debian.org>  Sun, 08 Dec 2019 21:02:49 +0100
 
diff --git a/debian/control b/debian/control
index 44640fab..5a0754c7 100644
--- a/debian/control
+++ b/debian/control
@@ -167,7 +167,6 @@ Description: Clang library - Common development package
 Package: libclang-cpp1-9
 Depends: libclang-cpp9, ${misc:Depends}
 Architecture: all
-Priority: optional
 Section: oldlibs
 Description: transitional package
  This is a transitional package. It can safely be removed.