diff --git a/src/state/opamFileTools.ml b/src/state/opamFileTools.ml
index 1c9b70cded2..8bb8a168b09 100644
--- a/src/state/opamFileTools.ml
+++ b/src/state/opamFileTools.ml
@@ -134,7 +134,7 @@ let is_installed_variable filter guarded_packages v =
   | (Some name) as package ->
     if OpamVariable.to_string (OpamVariable.Full.variable v) = "installed" then
       let env v =
-        if OpamPackage.equal (OpamVariable.Full.package v) package &&
+        if Option.equal OpamPackage.Name.equal (OpamVariable.Full.package v) package &&
            OpamVariable.(to_string (Full.variable v)) = "installed" then
           Some (B false)
         else