diff --git a/src/basic/namespace-util.c b/src/basic/namespace-util.c
index fff518ef96..97ed3d268f 100644
--- a/src/basic/namespace-util.c
+++ b/src/basic/namespace-util.c
@@ -359,7 +359,7 @@ int is_our_namespace(int fd, NamespaceType type) {
         int r;
 
         assert(fd >= 0);
-        assert(type < _NAMESPACE_TYPE_MAX);
+        assert(type >= 0 && type < _NAMESPACE_TYPE_MAX);
 
         r = fd_is_namespace(fd, type);
         if (r < 0)
diff --git a/src/core/execute-serialize.c b/src/core/execute-serialize.c
index 953b0d9894..55a5216042 100644
--- a/src/core/execute-serialize.c
+++ b/src/core/execute-serialize.c
@@ -3278,7 +3278,7 @@ static int exec_context_deserialize(ExecContext *c, FILE *f) {
 
                                         r = extract_first_word(&val, &options, NULL, EXTRACT_UNQUOTE);
                                         if (r < 0)
-                                                return -r;
+                                                return r;
 
                                         if (isempty(options) || streq(options, "rbind"))
                                                 rbind = true;
@@ -3337,7 +3337,7 @@ static int exec_context_deserialize(ExecContext *c, FILE *f) {
 
                                         r = extract_first_word(&val, &options, NULL, EXTRACT_UNQUOTE);
                                         if (r < 0)
-                                                return -r;
+                                                return r;
 
                                         if (isempty(options) || streq(options, "rbind"))
                                                 rbind = true;
diff --git a/src/core/manager.c b/src/core/manager.c
index bb8a735683..971f01903c 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1679,6 +1679,7 @@ static void manager_clear_jobs_and_units(Manager *m) {
         assert(!m->start_when_upheld_queue);
         assert(!m->stop_when_bound_queue);
         assert(!m->release_resources_queue);
+        assert(!m->stop_notify_queue);
 
         assert(hashmap_isempty(m->jobs));
         assert(hashmap_isempty(m->units));
diff --git a/src/core/unit.c b/src/core/unit.c
index 35691363e0..2205ad0e2b 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -4345,10 +4345,13 @@ static int unit_verify_contexts(const Unit *u) {
                 return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOEXEC), "PrivatePIDs= setting is only supported for service units. Refusing.");
 
         if ((ec->user || ec->dynamic_user || ec->group || ec->pam_name) && ec->private_users == PRIVATE_USERS_MANAGED)
-                return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOEXEC), "PrivateUsers=managed may not be used in combination with User=/DynamicUser=/Group=/PAMName=, refusing.");
+                return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOEXEC), "PrivateUsers=managed may not be used in combination with User=/DynamicUser=/Group=/PAMName=. Refusing.");
 
         if (ec->user_namespace_path && ec->private_users != PRIVATE_USERS_NO)
-                return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOEXEC), "PrivateUsers= may not be used with custom UserNamespacePath=, refusing.");
+                return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOEXEC), "PrivateUsers= may not be used with custom UserNamespacePath=. Refusing.");
+
+        if (ec->private_pids != PRIVATE_PIDS_NO && ec->pam_name)
+                return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOEXEC), "PAM is not supported under PrivatePIDs=. Refusing.");
 
         const KillContext *kc = unit_get_kill_context(u);
 
diff --git a/src/libsystemd/sd-daemon/sd-daemon.c b/src/libsystemd/sd-daemon/sd-daemon.c
index da5242c3b7..50bdcb1a23 100644
--- a/src/libsystemd/sd-daemon/sd-daemon.c
+++ b/src/libsystemd/sd-daemon/sd-daemon.c
@@ -637,8 +637,8 @@ static int pid_notify_with_fds_internal(
         }
 
         if (DEBUG_LOGGING) {
-                _cleanup_free_ char *escaped = xescape_full(state, "\"", /* console_width = */ SIZE_MAX, XESCAPE_8_BIT);
-                log_debug("Notify message sent to '%s': \"%s\"", e, escaped ?: state);
+                _cleanup_free_ char *escaped = shell_escape(state, "\"");
+                log_debug("Notify message sent to '%s': \"%s\"", e, strnull(escaped));
         }
 
         return 1;