diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index e274c3c0c..dda409955 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -2374,7 +2374,7 @@ static RegisterPrimOp primop_path({
           like `@`.
 
         - filter\
-          A function of the type expected by `builtins.filterSource`,
+          A function of the type expected by [`builtins.filterSource`](#builtins-filterSource),
           with the same semantics.
 
         - recursive\