diff --git a/src/data/CCMutHeap.mli b/src/data/CCMutHeap.mli
index eba23161..8bcf70ea 100644
--- a/src/data/CCMutHeap.mli
+++ b/src/data/CCMutHeap.mli
@@ -1,3 +1,15 @@
+(* This code is extracted from Msat ( https://github.com/Gbury/mSAT ).
+   As such it is under the Apache 2 License.
+*)
+
+(** {1 Mutable Heaps}
+
+    The classic binary heap in a vector.
+
+    {b STATUS}: experimental, this might change in breaking ways.
+
+    @since NEXT_RELEASE *)
+
 module type RANKED = CCMutHeap_intf.RANKED
 
 module type S = CCMutHeap_intf.S