diff --git a/pageserver/ctl/src/index_part.rs b/pageserver/ctl/src/index_part.rs
index 20018846f8fa..6cce2844c74a 100644
--- a/pageserver/ctl/src/index_part.rs
+++ b/pageserver/ctl/src/index_part.rs
@@ -11,7 +11,7 @@ pub(crate) async fn main(cmd: &IndexPartCmd) -> anyhow::Result<()> {
     match cmd {
         IndexPartCmd::Dump { path } => {
             let bytes = tokio::fs::read(path).await.context("read file")?;
-            let des: IndexPart = IndexPart::from_s3_bytes(&bytes).context("deserialize")?;
+            let des: IndexPart = IndexPart::from_json_bytes(&bytes).context("deserialize")?;
             let output = serde_json::to_string_pretty(&des).context("serialize output")?;
             println!("{output}");
             Ok(())
diff --git a/pageserver/src/tenant/remote_timeline_client/index.rs b/pageserver/src/tenant/remote_timeline_client/index.rs
index 3a74a4ed1186..d8a881a2c443 100644
--- a/pageserver/src/tenant/remote_timeline_client/index.rs
+++ b/pageserver/src/tenant/remote_timeline_client/index.rs
@@ -121,11 +121,11 @@ impl IndexPart {
         self.disk_consistent_lsn
     }
 
-    pub fn from_s3_bytes(bytes: &[u8]) -> Result<Self, serde_json::Error> {
+    pub fn from_json_bytes(bytes: &[u8]) -> Result<Self, serde_json::Error> {
         serde_json::from_slice::<IndexPart>(bytes)
     }
 
-    pub fn to_s3_bytes(&self) -> serde_json::Result<Vec<u8>> {
+    pub fn to_json_bytes(&self) -> serde_json::Result<Vec<u8>> {
         serde_json::to_vec(self)
     }
 
@@ -383,7 +383,7 @@ mod tests {
             last_aux_file_policy: None,
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -427,7 +427,7 @@ mod tests {
             last_aux_file_policy: None,
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -472,7 +472,7 @@ mod tests {
             last_aux_file_policy: None,
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -520,7 +520,7 @@ mod tests {
             last_aux_file_policy: None,
         };
 
-        let empty_layers_parsed = IndexPart::from_s3_bytes(empty_layers_json.as_bytes()).unwrap();
+        let empty_layers_parsed = IndexPart::from_json_bytes(empty_layers_json.as_bytes()).unwrap();
 
         assert_eq!(empty_layers_parsed, expected);
     }
@@ -563,7 +563,7 @@ mod tests {
             last_aux_file_policy: None,
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -609,7 +609,7 @@ mod tests {
             last_aux_file_policy: None,
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -660,7 +660,7 @@ mod tests {
             last_aux_file_policy: Some(AuxFilePolicy::V2),
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -716,7 +716,7 @@ mod tests {
             last_aux_file_policy: Default::default(),
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -773,7 +773,7 @@ mod tests {
             last_aux_file_policy: Default::default(),
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
@@ -835,7 +835,7 @@ mod tests {
             archived_at: None,
         };
 
-        let part = IndexPart::from_s3_bytes(example.as_bytes()).unwrap();
+        let part = IndexPart::from_json_bytes(example.as_bytes()).unwrap();
         assert_eq!(part, expected);
     }
 
diff --git a/pageserver/src/tenant/remote_timeline_client/upload.rs b/pageserver/src/tenant/remote_timeline_client/upload.rs
index 5a2b7bd08fad..0cd5d05aa276 100644
--- a/pageserver/src/tenant/remote_timeline_client/upload.rs
+++ b/pageserver/src/tenant/remote_timeline_client/upload.rs
@@ -41,7 +41,7 @@ pub(crate) async fn upload_index_part<'a>(
     pausable_failpoint!("before-upload-index-pausable");
 
     // FIXME: this error comes too late
-    let serialized = index_part.to_s3_bytes()?;
+    let serialized = index_part.to_json_bytes()?;
     let serialized = Bytes::from(serialized);
 
     let index_part_size = serialized.len();