diff --git a/tests/build.rs b/tests/build.rs
index f39cab1c4..446c8cf0e 100644
--- a/tests/build.rs
+++ b/tests/build.rs
@@ -99,7 +99,7 @@ fn main() {
         .compile_protos(&[src.join("derive_copy.proto")], includes)
         .unwrap();
 
-    config
+    prost_build::Config::new()
         .compile_protos(&[src.join("default_string_escape.proto")], includes)
         .unwrap();
 
diff --git a/tests/src/default_string_escape.rs b/tests/src/default_string_escape.rs
new file mode 100644
index 000000000..4c576d5f5
--- /dev/null
+++ b/tests/src/default_string_escape.rs
@@ -0,0 +1,7 @@
+include!(concat!(env!("OUT_DIR"), "/default_string_escape.rs"));
+
+#[test]
+fn test_default_string_escape() {
+    let msg = Person::default();
+    assert_eq!(msg.name, r#"["unknown"]"#);
+}
diff --git a/tests/src/lib.rs b/tests/src/lib.rs
index adf68a4a3..00b2b67b0 100644
--- a/tests/src/lib.rs
+++ b/tests/src/lib.rs
@@ -78,6 +78,9 @@ mod recursive_oneof;
 #[cfg(test)]
 mod groups;
 
+#[cfg(test)]
+mod default_string_escape;
+
 mod test_enum_named_option_value {
     include!(concat!(env!("OUT_DIR"), "/myenum.optionn.rs"));
 }
@@ -115,10 +118,6 @@ pub mod proto3 {
     }
 }
 
-pub mod default_string_escape {
-    include!(concat!(env!("OUT_DIR"), "/default_string_escape.rs"));
-}
-
 #[cfg(not(feature = "std"))]
 use alloc::vec::Vec;
 
@@ -394,12 +393,6 @@ mod tests {
         <() as Message>::decode(&buf[..]).err().unwrap();
     }
 
-    #[test]
-    fn test_default_string_escape() {
-        let msg = default_string_escape::Person::default();
-        assert_eq!(msg.name, r#"["unknown"]"#);
-    }
-
     #[test]
     fn test_proto3_presence() {
         let msg = proto3::presence::A {