diff --git a/serde_core/src/integer128.rs b/serde/src/integer128.rs
similarity index 100%
rename from serde_core/src/integer128.rs
rename to serde/src/integer128.rs
diff --git a/serde/src/lib.rs b/serde/src/lib.rs
index fd9a1a03..5a4f89dc 100644
--- a/serde/src/lib.rs
+++ b/serde/src/lib.rs
@@ -231,10 +231,12 @@ macro_rules! tri {
 ////////////////////////////////////////////////////////////////////////////////
 
 pub use serde_core::{
-    de, forward_to_deserialize_any, ser, serde_if_integer128, Deserialize, Deserializer, Serialize,
-    Serializer,
+    de, forward_to_deserialize_any, ser, Deserialize, Deserializer, Serialize, Serializer,
 };
 
+#[macro_use]
+mod integer128;
+
 // Used by generated code and doc tests. Not public API.
 #[doc(hidden)]
 #[path = "private/mod.rs"]
diff --git a/serde_core/src/lib.rs b/serde_core/src/lib.rs
index b27126b9..0ae7ccda 100644
--- a/serde_core/src/lib.rs
+++ b/serde_core/src/lib.rs
@@ -240,9 +240,6 @@ macro_rules! tri {
 #[macro_use]
 mod macros;
 
-#[macro_use]
-mod integer128;
-
 pub mod de;
 pub mod ser;