diff --git a/src/lib/server/tmpl_tokenize.c b/src/lib/server/tmpl_tokenize.c
index e15247659c04..df05f6d954f8 100644
--- a/src/lib/server/tmpl_tokenize.c
+++ b/src/lib/server/tmpl_tokenize.c
@@ -3278,14 +3278,7 @@ fr_slen_t tmpl_afrom_substr(TALLOC_CTX *ctx, tmpl_t **out,
 		 *	so that their instance data will be created.
 		 */
 		if (head) {
-			int rcode;
-
-			if (!t_rules->at_runtime) {
-				rcode = xlat_bootstrap(head);
-			} else {
-				rcode = xlat_instantiate_ephemeral(head, t_rules->xlat.runtime_el);
-			}
-			if (rcode < 0) {
+			if (xlat_finalize(head, t_rules) < 0) {
 				fr_strerror_const("Failed to bootstrap xlat");
 				FR_SBUFF_ERROR_RETURN(&our_in);
 			}
diff --git a/src/lib/unlang/xlat.h b/src/lib/unlang/xlat.h
index b86be7fe15a3..d9a39a3cf581 100644
--- a/src/lib/unlang/xlat.h
+++ b/src/lib/unlang/xlat.h
@@ -466,6 +466,8 @@ int		xlat_bootstrap(xlat_exp_head_t *root);
 
 void		xlat_instances_free(void);
 
+int		xlat_finalize(xlat_exp_head_t *head, tmpl_rules_t const *t_rules); /* xlat_bootstrap() or xlat_instantiate_ephemeral() */
+
 /*
  *	xlat_purify.c
  */
diff --git a/src/lib/unlang/xlat_expr.c b/src/lib/unlang/xlat_expr.c
index 49b3a4e2b7ff..0bbdadc6434e 100644
--- a/src/lib/unlang/xlat_expr.c
+++ b/src/lib/unlang/xlat_expr.c
@@ -2833,7 +2833,6 @@ static const fr_sbuff_term_t operator_terms = FR_SBUFF_TERMS(
 static fr_slen_t xlat_tokenize_expression_internal(TALLOC_CTX *ctx, xlat_exp_head_t **out, fr_sbuff_t *in,
 						   fr_sbuff_parse_rules_t const *p_rules, tmpl_rules_t const *t_rules, bool cond)
 {
-	int rcode;
 	ssize_t slen;
 	fr_sbuff_parse_rules_t *bracket_rules = NULL;
 	fr_sbuff_parse_rules_t *terminal_rules = NULL;
@@ -2908,12 +2907,7 @@ static fr_slen_t xlat_tokenize_expression_internal(TALLOC_CTX *ctx, xlat_exp_hea
 	 *	Add nodes that need to be bootstrapped to
 	 *	the registry.
 	 */
-	if (!t_rules || !t_rules->xlat.runtime_el) {
-		rcode = xlat_bootstrap(head);
-	} else {
-		rcode = xlat_instantiate_ephemeral(head, t_rules->xlat.runtime_el);
-	}
-	if (rcode < 0) {
+	if (xlat_finalize(head, t_rules) < 0) {
 		talloc_free(head);
 		return -1;
 	}
diff --git a/src/lib/unlang/xlat_inst.c b/src/lib/unlang/xlat_inst.c
index 9713b0a7a1a9..f00c4ec2bc7b 100644
--- a/src/lib/unlang/xlat_inst.c
+++ b/src/lib/unlang/xlat_inst.c
@@ -348,9 +348,31 @@ static int _xlat_instantiate_ephemeral_walker(xlat_exp_t *node, void *uctx)
 	return 0;
 }
 
+
+/** Bootstrap static xlats, or instantiate ephemeral ones.
+ *
+ *  @note - this function should be called when we have a
+ *  #tmpl_rules_t.  i.e. instead of calling xlat_bootstrap() or
+ *  xlat_instantiate_ephemeral()
+ *
+ * @param[in] head of xlat tree to create instance data for.
+ * @param[in] t_rules parsing rules with #fr_event_list_t
+ */
+int xlat_finalize(xlat_exp_head_t *head, tmpl_rules_t const *t_rules)
+{
+	if (!t_rules || !t_rules->xlat.runtime_el) {
+		fr_assert(!t_rules->at_runtime);
+		return xlat_bootstrap(head);
+	}
+
+	fr_assert(t_rules->at_runtime);
+	return xlat_instantiate_ephemeral(head, t_rules->xlat.runtime_el);
+}
+
 /** Create instance data for "ephemeral" xlats
  *
- * @note This must only be used for xlats created at runtime.
+ * @note This function should only be called from routines which get
+ * passed a #request_t.
  *
  * @param[in] head of xlat tree to create instance data for.
  * @param[in] el event list used to run any instantiate data
@@ -587,9 +609,9 @@ static int _xlat_bootstrap_walker(xlat_exp_t *node, UNUSED void *uctx)
 
 /** Create instance data for "permanent" xlats
  *
- * @note This must only be used for xlats created during startup.
+ * @note This must only be used for xlats which are read from the configuration files.
  *	 IF THIS IS CALLED FOR XLATS TOKENIZED AT RUNTIME YOU WILL LEAK LARGE AMOUNTS OF MEMORY.
- *	 USE xlat_instantiate_request() INSTEAD.
+ *	 If the caller has a #tmpl_rules_t, it should call xlat_finalize() instead.
  *
  * @param[in] head of xlat tree to create instance data for.
  */
diff --git a/src/lib/unlang/xlat_tokenize.c b/src/lib/unlang/xlat_tokenize.c
index c362907f2131..945dcba9e59f 100644
--- a/src/lib/unlang/xlat_tokenize.c
+++ b/src/lib/unlang/xlat_tokenize.c
@@ -1860,7 +1860,6 @@ fr_slen_t xlat_tokenize_argv(TALLOC_CTX *ctx, xlat_exp_head_t **out, fr_sbuff_t
 fr_slen_t xlat_tokenize(TALLOC_CTX *ctx, xlat_exp_head_t **out, fr_sbuff_t *in,
 			fr_sbuff_parse_rules_t const *p_rules, tmpl_rules_t const *t_rules)
 {
-	int rcode;
 	fr_sbuff_t	our_in = FR_SBUFF(in);
 	xlat_exp_head_t	*head;
 
@@ -1881,12 +1880,7 @@ fr_slen_t xlat_tokenize(TALLOC_CTX *ctx, xlat_exp_head_t **out, fr_sbuff_t *in,
 	 *	Add nodes that need to be bootstrapped to
 	 *	the registry.
 	 */
-	if (!t_rules || !t_rules->xlat.runtime_el) {
-		rcode = xlat_bootstrap(head);
-	} else {
-		rcode = xlat_instantiate_ephemeral(head, t_rules->xlat.runtime_el);
-	}
-	if (rcode < 0) {
+	if (xlat_finalize(head, t_rules) < 0) {
 		talloc_free(head);
 		return 0;
 	}