diff --git a/rslib/src/media/files.rs b/rslib/src/media/files.rs
index c5523f5f1..b6bd4d192 100644
--- a/rslib/src/media/files.rs
+++ b/rslib/src/media/files.rs
@@ -267,24 +267,26 @@ pub(super) fn add_file_from_ankiweb(
     fname: &str,
     data: &[u8],
 ) -> Result<AddedFile> {
+    let sha1 = sha1_of_data(data);
     let normalized = normalize_filename(fname);
 
-    let path = media_folder.join(normalized.as_ref());
-    fs::write(&path, data)?;
-
-    let sha1 = sha1_of_data(data);
+    // if the filename is already valid, we can write the file directly
+    let (renamed_from, path) = if let Cow::Borrowed(_) = normalized {
+        let path = media_folder.join(normalized.as_ref());
+        fs::write(&path, data)?;
+        (None, path)
+    } else {
+        debug!("non-normalized filename received {}", fname);
+        // ankiweb sent us a non-normalized filename, so we'll rename it
+        let new_name = add_data_to_folder_uniquely(media_folder, fname, data, sha1)?;
+        (
+            Some(new_name.to_string()),
+            media_folder.join(new_name.as_ref()),
+        )
+    };
 
     let mtime = mtime_as_i64(path)?;
 
-    // fixme: could we use the info sent from the server for the hash instead
-    // of hashing it here and returning hash?
-
-    let renamed_from = if let Cow::Borrowed(_) = normalized {
-        None
-    } else {
-        Some(fname.to_string())
-    };
-
     Ok(AddedFile {
         fname: normalized.to_string(),
         sha1,
diff --git a/rslib/src/media/sync.rs b/rslib/src/media/sync.rs
index 2bbdb58a1..94cfdb362 100644
--- a/rslib/src/media/sync.rs
+++ b/rslib/src/media/sync.rs
@@ -24,7 +24,7 @@ static SYNC_MAX_FILES: usize = 25;
 static SYNC_MAX_BYTES: usize = (2.5 * 1024.0 * 1024.0) as usize;
 static SYNC_SINGLE_FILE_MAX_BYTES: usize = 100 * 1024 * 1024;
 
-// fixme: non-normalized filenames on ankiweb
+// fixme: dir mod handling when downloading files in a sync
 // fixme: concurrent modifications during upload step
 
 /// The counts are not cumulative - the progress hook should accumulate them.
@@ -507,18 +507,41 @@ fn record_removals(ctx: &mut MediaDatabaseContext, removals: &[&String]) -> Resu
 
 fn record_additions(ctx: &mut MediaDatabaseContext, additions: Vec<AddedFile>) -> Result<()> {
     for file in additions {
-        let entry = MediaEntry {
-            fname: file.fname.to_string(),
-            sha1: Some(file.sha1),
-            mtime: file.mtime,
-            sync_required: false,
-        };
-        debug!(
-            "marking added: {} {}",
-            entry.fname,
-            hex::encode(entry.sha1.as_ref().unwrap())
-        );
-        ctx.set_entry(&entry)?;
+        if let Some(renamed) = file.renamed_from {
+            // the file AnkiWeb sent us wasn't normalized, so we need to record
+            // the old file name as a deletion
+            debug!("marking non-normalized file as deleted: {}", renamed);
+            let mut entry = MediaEntry {
+                fname: renamed,
+                sha1: None,
+                mtime: 0,
+                sync_required: true,
+            };
+            ctx.set_entry(&entry)?;
+            // and upload the new filename to ankiweb
+            debug!("marking renamed file as needing upload: {}", file.fname);
+            entry = MediaEntry {
+                fname: file.fname.to_string(),
+                sha1: Some(file.sha1),
+                mtime: file.mtime,
+                sync_required: true,
+            };
+            ctx.set_entry(&entry)?;
+        } else {
+            // a normal addition
+            let entry = MediaEntry {
+                fname: file.fname.to_string(),
+                sha1: Some(file.sha1),
+                mtime: file.mtime,
+                sync_required: false,
+            };
+            debug!(
+                "marking added: {} {}",
+                entry.fname,
+                hex::encode(entry.sha1.as_ref().unwrap())
+            );
+            ctx.set_entry(&entry)?;
+        }
     }
 
     Ok(())