diff --git a/test_suite/tests/ui/default-attribute/enum.rs b/test_suite/tests/ui/default-attribute/enum.rs
index e0ecc9f0..f747e94c 100644
--- a/test_suite/tests/ui/default-attribute/enum.rs
+++ b/test_suite/tests/ui/default-attribute/enum.rs
@@ -6,3 +6,5 @@ extern crate serde_derive;
 enum E {
     S { f: u8 },
 }
+
+fn main() {}
diff --git a/test_suite/tests/ui/default-attribute/enum_path.rs b/test_suite/tests/ui/default-attribute/enum_path.rs
index 3c1ff45b..9a261b16 100644
--- a/test_suite/tests/ui/default-attribute/enum_path.rs
+++ b/test_suite/tests/ui/default-attribute/enum_path.rs
@@ -6,3 +6,5 @@ extern crate serde_derive;
 enum E {
     S { f: u8 },
 }
+
+fn main() {}
diff --git a/test_suite/tests/ui/precondition/deserialize_de_lifetime.rs b/test_suite/tests/ui/precondition/deserialize_de_lifetime.rs
index 7ce4b6d8..5dfe6245 100644
--- a/test_suite/tests/ui/precondition/deserialize_de_lifetime.rs
+++ b/test_suite/tests/ui/precondition/deserialize_de_lifetime.rs
@@ -5,3 +5,5 @@ extern crate serde_derive;
 struct S<'de> {
     s: &'de str,
 }
+
+fn main() {}
diff --git a/test_suite/tests/ui/precondition/deserialize_dst.rs b/test_suite/tests/ui/precondition/deserialize_dst.rs
index a0aceaa3..4f62a04e 100644
--- a/test_suite/tests/ui/precondition/deserialize_dst.rs
+++ b/test_suite/tests/ui/precondition/deserialize_dst.rs
@@ -6,3 +6,5 @@ struct S {
     string: String,
     slice: [u8],
 }
+
+fn main() {}
diff --git a/test_suite/tests/ui/type-attribute/from.rs b/test_suite/tests/ui/type-attribute/from.rs
index 94f9b1f0..f59ed2af 100644
--- a/test_suite/tests/ui/type-attribute/from.rs
+++ b/test_suite/tests/ui/type-attribute/from.rs
@@ -9,3 +9,5 @@ enum TestOne {
     Two,
     Three,
 }
+
+fn main() {}
diff --git a/test_suite/tests/ui/type-attribute/into.rs b/test_suite/tests/ui/type-attribute/into.rs
index 88cdf33f..c0383eff 100644
--- a/test_suite/tests/ui/type-attribute/into.rs
+++ b/test_suite/tests/ui/type-attribute/into.rs
@@ -9,3 +9,5 @@ enum TestOne {
     Two,
     Three,
 }
+
+fn main() {}