diff --git a/src/dune_file.ml b/src/dune_file.ml
index 6b24ca8aa394..d4b4fce43c82 100644
--- a/src/dune_file.ml
+++ b/src/dune_file.ml
@@ -637,7 +637,7 @@ module Buildable = struct
     and preprocess =
       field "preprocess" Preprocess_map.decode ~default:Preprocess_map.default
     and variants =
-      field "variants" ((list Variant.decode) >>| Variant.Set.of_list)
+      field "variants" (list Variant.decode >>| Variant.Set.of_list)
             ~default:Variant.Set.empty
     and preprocessor_deps =
       field "preprocessor_deps" (list Dep_conf.decode) ~default:[]
@@ -886,11 +886,11 @@ module Library = struct
            >>= fun () -> located Lib_name.decode)
        and variant =
          field_o "variant" (
-           Syntax.since Stanza.syntax (1, 7)
+           Syntax.since Stanza.syntax (1, 8)
            >>= fun () -> located Variant.decode)
        and default_implementation =
          field_o "default_implementation" (
-           Syntax.since Stanza.syntax (1, 7)
+           Syntax.since Stanza.syntax (1, 8)
            >>= fun () -> located Lib_name.decode)
        and private_modules =
          field_o "private_modules" (
diff --git a/test/blackbox-tests/test-cases/variants/default-impl-not-virtual-lib/dune-project b/test/blackbox-tests/test-cases/variants/default-impl-not-virtual-lib/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/default-impl-not-virtual-lib/dune-project
+++ b/test/blackbox-tests/test-cases/variants/default-impl-not-virtual-lib/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/default-impl/dune-project b/test/blackbox-tests/test-cases/variants/default-impl/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/default-impl/dune-project
+++ b/test/blackbox-tests/test-cases/variants/default-impl/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/dependency-cycle/dune-project b/test/blackbox-tests/test-cases/variants/dependency-cycle/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/dependency-cycle/dune-project
+++ b/test/blackbox-tests/test-cases/variants/dependency-cycle/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/multiple-implementations-for-variants/dune-project b/test/blackbox-tests/test-cases/variants/multiple-implementations-for-variants/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/multiple-implementations-for-variants/dune-project
+++ b/test/blackbox-tests/test-cases/variants/multiple-implementations-for-variants/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/resolution-priority/dune-project b/test/blackbox-tests/test-cases/variants/resolution-priority/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/resolution-priority/dune-project
+++ b/test/blackbox-tests/test-cases/variants/resolution-priority/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/variant-not-implementation/dune-project b/test/blackbox-tests/test-cases/variants/variant-not-implementation/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/variant-not-implementation/dune-project
+++ b/test/blackbox-tests/test-cases/variants/variant-not-implementation/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/variant-with-concrete-impl/dune-project b/test/blackbox-tests/test-cases/variants/variant-with-concrete-impl/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/variant-with-concrete-impl/dune-project
+++ b/test/blackbox-tests/test-cases/variants/variant-with-concrete-impl/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/variants/variants-base/dune-project b/test/blackbox-tests/test-cases/variants/variants-base/dune-project
index fd5c747c6875..bc63500b73c0 100644
--- a/test/blackbox-tests/test-cases/variants/variants-base/dune-project
+++ b/test/blackbox-tests/test-cases/variants/variants-base/dune-project
@@ -1 +1 @@
-(lang dune 1.7)
\ No newline at end of file
+(lang dune 1.8)
\ No newline at end of file