diff --git a/guix-data-service/comparison.scm b/guix-data-service/comparison.scm
index 3eee5f7..4907357 100644
--- a/guix-data-service/comparison.scm
+++ b/guix-data-service/comparison.scm
@@ -340,7 +340,13 @@ SELECT base_packages.name, base_packages.version,
                'status',  latest_build_status.status,
                'timestamp',  latest_build_status.timestamp,
                'build_for_equivalent_derivation',
-               builds.derivation_file_name != base_packages.file_name
+               builds.derivation_file_name != base_packages.file_name,
+               'potentially_blocked', EXISTS (
+                  SELECT 1
+                  FROM blocked_builds
+                  WHERE blocked_derivation_output_details_set_id
+                         = builds.derivation_output_details_set_id
+               )
              )
              ORDER BY latest_build_status.timestamp
            )
@@ -365,7 +371,13 @@ SELECT base_packages.name, base_packages.version,
                'status',  latest_build_status.status,
                'timestamp',  latest_build_status.timestamp,
                'build_for_equivalent_derivation',
-               builds.derivation_file_name != target_packages.file_name
+               builds.derivation_file_name != target_packages.file_name,
+               'potentially_blocked', EXISTS (
+                  SELECT 1
+                  FROM blocked_builds
+                  WHERE blocked_derivation_output_details_set_id
+                         = builds.derivation_output_details_set_id
+               )
              )
              ORDER BY latest_build_status.timestamp
            )