diff --git a/src/pg_query_fingerprint.c b/src/pg_query_fingerprint.c
index 8e15b821..0c77a856 100644
--- a/src/pg_query_fingerprint.c
+++ b/src/pg_query_fingerprint.c
@@ -5,6 +5,7 @@
 #include "pg_query_fingerprint.h"
 
 #include "postgres.h"
+#include "miscadmin.h"
 #include "xxhash/xxhash.h"
 #include "lib/ilist.h"
 
@@ -263,6 +264,7 @@ _fingerprintFreeContext(FingerprintContext *ctx) {
 void
 _fingerprintNode(FingerprintContext *ctx, const void *obj, const void *parent, char *field_name, unsigned int depth)
 {
+	check_stack_depth();
 	// Some queries are overly complex in their parsetree - lets consistently cut them off at 100 nodes deep
 	if (depth >= 100) {
 		return;
diff --git a/src/pg_query_json_plpgsql.c b/src/pg_query_json_plpgsql.c
index ec5134bd..693a05ad 100644
--- a/src/pg_query_json_plpgsql.c
+++ b/src/pg_query_json_plpgsql.c
@@ -1,4 +1,6 @@
 #include "pg_query.h"
+#include "postgres.h"
+#include "miscadmin.h"
 #include "pg_query_json_plpgsql.h"
 
 #include "pg_query_json_helper.c"
@@ -138,6 +140,7 @@ static void dump_type(StringInfo out, PLpgSQL_type *node);
 static void
 dump_stmt(StringInfo out, PLpgSQL_stmt *node)
 {
+	check_stack_depth();
 	appendStringInfoChar(out, '{');
 	switch (node->cmd_type)
 	{
@@ -627,6 +630,7 @@ dump_getdiag_item(StringInfo out, PLpgSQL_diag_item *node)
 static void
 dump_expr(StringInfo out, PLpgSQL_expr *node)
 {
+	check_stack_depth();
 	WRITE_NODE_TYPE("PLpgSQL_expr");
 
 	WRITE_STRING_FIELD(query, query, query);
@@ -812,7 +816,10 @@ pg_query_plpgsql_reset_aliases(void)
 	int i;
 	for (i = 0; i < plpgsql_naliases; i++)
 		free(plpgsql_aliases[i].name);
+	free(plpgsql_aliases);
+	plpgsql_aliases = NULL;
 	plpgsql_naliases = 0;
+	plpgsql_aliases_size = 0;
 }
 
 void
diff --git a/src/pg_query_outfuncs_json.c b/src/pg_query_outfuncs_json.c
index e5025ed6..0801ed47 100644
--- a/src/pg_query_outfuncs_json.c
+++ b/src/pg_query_outfuncs_json.c
@@ -1,6 +1,7 @@
 #include "pg_query_outfuncs.h"
 
 #include "postgres.h"
+#include "miscadmin.h"
 
 #include <ctype.h>
 
@@ -289,6 +290,7 @@ _outAConst(StringInfo out, const A_Const *node)
 static void
 _outNode(StringInfo out, const void *obj)
 {
+	check_stack_depth();
 	if (obj == NULL)
 	{
 		appendStringInfoString(out, "null");
diff --git a/src/pg_query_outfuncs_protobuf.c b/src/pg_query_outfuncs_protobuf.c
index 64ccdf1b..c7bcd34a 100644
--- a/src/pg_query_outfuncs_protobuf.c
+++ b/src/pg_query_outfuncs_protobuf.c
@@ -1,6 +1,7 @@
 #include "pg_query_outfuncs.h"
 
 #include "postgres.h"
+#include "miscadmin.h"
 #include <ctype.h>
 #include "access/relation.h"
 #include "nodes/parsenodes.h"
@@ -246,6 +247,7 @@ _outAConst(PgQuery__AConst* out, const A_Const *node)
 static void
 _outNode(PgQuery__Node* out, const void *obj)
 {
+	check_stack_depth();
 	if (obj == NULL)
 		return; // Keep out as NULL
 
diff --git a/src/pg_query_parse.c b/src/pg_query_parse.c
index 3f2c111a..60077bbf 100644
--- a/src/pg_query_parse.c
+++ b/src/pg_query_parse.c
@@ -135,9 +135,39 @@ PgQueryParseResult pg_query_parse_opts(const char* input, int parser_options)
 	result.stderr_buffer = parsetree_and_error.stderr_buffer;
 	result.error = parsetree_and_error.error;
 
-	tree_json = pg_query_nodes_to_json(parsetree_and_error.tree);
-	result.parse_tree = strdup(tree_json);
-	pfree(tree_json);
+	if (result.error == NULL)
+	{
+		PG_TRY();
+		{
+			tree_json = pg_query_nodes_to_json(parsetree_and_error.tree);
+			result.parse_tree = strdup(tree_json);
+			pfree(tree_json);
+		}
+		PG_CATCH();
+		{
+			ErrorData* error_data;
+			PgQueryError* error;
+
+			MemoryContextSwitchTo(ctx);
+			error_data = CopyErrorData();
+			error = malloc(sizeof(PgQueryError));
+			error->message   = strdup(error_data->message);
+			error->filename  = strdup(error_data->filename);
+			error->funcname  = strdup(error_data->funcname);
+			error->context   = NULL;
+			error->lineno    = error_data->lineno;
+			error->cursorpos = error_data->cursorpos;
+			result.error = error;
+			FlushErrorState();
+		}
+		PG_END_TRY();
+	}
+	else
+	{
+		tree_json = pg_query_nodes_to_json(parsetree_and_error.tree);
+		result.parse_tree = strdup(tree_json);
+		pfree(tree_json);
+	}
 
 	pg_query_exit_memory_context(ctx);
 
diff --git a/src/pg_query_parse_plpgsql.c b/src/pg_query_parse_plpgsql.c
index 79402515..ca46f85f 100644
--- a/src/pg_query_parse_plpgsql.c
+++ b/src/pg_query_parse_plpgsql.c
@@ -671,6 +671,8 @@ PgQueryPlpgsqlParseResult pg_query_parse_plpgsql(const char* input)
 	result.plpgsql_funcs[strlen(result.plpgsql_funcs) - 1] = ']';
 
 	free(parse_result.stderr_buffer);
+	/* Drop the aliases recorded during this compile so nothing outlives the call */
+	pg_query_plpgsql_reset_aliases();
 	pg_query_exit_memory_context(ctx);
 
 	return result;
diff --git a/src/postgres/src_backend_utils_misc_stack_depth.c b/src/postgres/src_backend_utils_misc_stack_depth.c
index b1b6690f..eecb6b28 100644
--- a/src/postgres/src_backend_utils_misc_stack_depth.c
+++ b/src/postgres/src_backend_utils_misc_stack_depth.c
@@ -146,3 +146,14 @@ stack_is_too_deep(void)
 #if defined(HAVE_GETRLIMIT)
 #else
 #endif
+
+/* libpg-query-node: set the stack-depth reference point and limit from the embedder. */
+void
+pg_query_set_stack_limit(size_t bytes)
+{
+	char		here;
+
+	stack_base_ptr = &here;
+	max_stack_depth_bytes = (ssize_t) bytes;
+	max_stack_depth = (int) (bytes / 1024);
+}
diff --git a/src/postgres_deparse.c b/src/postgres_deparse.c
index e2bdf87d..15fd2466 100644
--- a/src/postgres_deparse.c
+++ b/src/postgres_deparse.c
@@ -1,6 +1,7 @@
 #include "postgres_deparse.h"
 
 #include "postgres.h"
+#include "miscadmin.h"
 #include "catalog/index.h"
 #include "catalog/pg_am.h"
 #include "catalog/pg_attribute.h"
@@ -784,6 +785,7 @@ static void deparseCExpr(DeparseState *state, Node *node);
 // "a_expr" in gram.y
 static void deparseExpr(DeparseState *state, Node *node, DeparseNodeContext context)
 {
+	check_stack_depth();
 	if (node == NULL)
 		return;
 	switch (nodeTag(node))