diff --git a/host/src/main.rs b/host/src/main.rs
index fd9de2a..c190b06 100644
--- a/host/src/main.rs
+++ b/host/src/main.rs
@@ -302,7 +302,13 @@ fn main() -> io::Result<()> {
                 attributes.merge(&existing.1);
                 *existing = (curr_time, attributes);
             } else {
-                data.insert(event.tab_info.tab_id, (curr_time, attributes));
+                // We some times receive events with null titles and window ids, for which
+                // we never receive remove events afterwards. Not sure what those are,
+                // they might be the result of a race condition on the extension side, but
+                // as a workaround we ignore them here.
+                if attributes.title.is_some() && attributes.window_id.is_some() {
+                    data.insert(event.tab_info.tab_id, (curr_time, attributes));
+                }
             }
         }
     }
diff --git a/integration_tests/run_tests.sh b/integration_tests/run_tests.sh
index ec2a5f1..02fd76e 100755
--- a/integration_tests/run_tests.sh
+++ b/integration_tests/run_tests.sh
@@ -102,23 +102,33 @@ function run-suite() {
     local invocation=( dbus-launch "$VIRTUALENV_DIR"/bin/python3 tabreport_tests.py "$ff_version" "$xpi_file" )
     tmpfile=
     if [ "$REPORT_MD_FILE" != "" ]; then
+        echo "Outputting to ${REPORT_MD_FILE}" >&2
         tmpfile="$(mktemp)"
         invocation=( "${invocation[@]}" -o "$tmpfile" )
     fi
 
+    result=0
     if [ "$host_target_version" != "" ]; then
         echo "Running integration tests with Firefox $ff_version and native host version ${host_target_version}" >&2
         echo "" >&2
+        set +e
         HOST_TARGET_VERSION="$host_target_version" "${invocation[@]}"
+        result=$?
+        set -e
     else
         echo "Running integration tests with Firefox $ff_version" >&2
         echo "" >&2
+        set +e
         "${invocation[@]}"
+        result=$?
+        set -e
     fi
 
     if [ "$REPORT_MD_FILE" != "" ]; then
         cat "$tmpfile" >> "$REPORT_MD_FILE"
     fi
+
+    return "$result"
 }
 
 while read -r ff_version; do