diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58ad529a..45b4a0c3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## Unreleased
+
+**Fixes**
+- js: Prefer `"debug_id"` for sourcemap debug IDs. ([#878](https://github.com/getsentry/symbolic/pull/878)).
+
 ## 12.12.2
 
 **Fixes**
diff --git a/symbolic-debuginfo/src/js.rs b/symbolic-debuginfo/src/js.rs
index 5da34c8e..bf3341fe 100644
--- a/symbolic-debuginfo/src/js.rs
+++ b/symbolic-debuginfo/src/js.rs
@@ -31,10 +31,10 @@ pub fn discover_sourcemaps_location(contents: &str) -> Option<&str> {
 /// Quickly reads the embedded `debug_id` key from a source map.
 ///
 /// Both `debugId` and `debug_id` are supported as field names. If both
-/// are set, the former takes precedence.
+/// are set, the latter takes precedence.
 pub fn discover_sourcemap_embedded_debug_id(contents: &str) -> Option<DebugId> {
     // Deserialize from `"debugId"` or `"debug_id"`,
-    // preferring the former.
+    // preferring the latter.
     #[derive(Deserialize)]
     struct DebugIdInSourceMap {
         #[serde(rename = "debugId")]
@@ -45,7 +45,7 @@ pub fn discover_sourcemap_embedded_debug_id(contents: &str) -> Option<DebugId> {
 
     serde_json::from_str(contents)
         .ok()
-        .and_then(|x: DebugIdInSourceMap| x.debug_id_new.or(x.debug_id_old))
+        .and_then(|x: DebugIdInSourceMap| x.debug_id_old.or(x.debug_id_new))
 }
 
 /// Parses a `debugId` comment in a file to discover a sourcemap's debug ID.
@@ -103,8 +103,8 @@ mod tests {
          "sources":["coolstuff.js"],
          "names":["x","alert"],
          "mappings":"AAAA,GAAIA,GAAI,EACR,IAAIA,GAAK,EAAG,CACVC,MAAM",
-         "debugId":"00000000-0000-0000-0000-000000000000",
-         "debug_id":"11111111-1111-1111-1111-111111111111"
+         "debug_id":"00000000-0000-0000-0000-000000000000",
+         "debugId":"11111111-1111-1111-1111-111111111111"
      }"#;
 
         assert_eq!(