diff --git a/.github/workflows/release-please.yml b/.github/workflows/release-please.yml
index 213b356c..4a2d1aba 100644
--- a/.github/workflows/release-please.yml
+++ b/.github/workflows/release-please.yml
@@ -8,6 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       paths_released: ${{ steps.manifest_release.outputs.paths_released }}
+      releases_created: ${{ steps.manifest_release.outputs.releases_created }}
     steps:
       - uses: google-github-actions/release-please-action@v4
         id: manifest_release
diff --git a/packages/istanbul-lib-source-maps/lib/map-store.js b/packages/istanbul-lib-source-maps/lib/map-store.js
index 22c789a7..31fd986e 100644
--- a/packages/istanbul-lib-source-maps/lib/map-store.js
+++ b/packages/istanbul-lib-source-maps/lib/map-store.js
@@ -192,13 +192,15 @@ class MapStore {
 
                     const smc = new TraceMap(obj);
                     smc.sources.forEach(s => {
-                        const content = sourceContentFor(smc, s);
-                        if (content) {
-                            const sourceFilePath = pathutils.relativeTo(
-                                s,
-                                filePath
-                            );
-                            this.sourceStore.set(sourceFilePath, content);
+                        if (s) {
+                            const content = sourceContentFor(smc, s);
+                            if (content) {
+                                const sourceFilePath = pathutils.relativeTo(
+                                    s,
+                                    filePath
+                                );
+                                this.sourceStore.set(sourceFilePath, content);
+                            }
                         }
                     });