diff --git a/src/parse_execution.cpp b/src/parse_execution.cpp
index 921faf829..f05b6cecf 100644
--- a/src/parse_execution.cpp
+++ b/src/parse_execution.cpp
@@ -329,10 +329,7 @@ parse_execution_result_t parse_execution_context_t::run_if_statement(
 }
 
 parse_execution_result_t parse_execution_context_t::run_begin_statement(
-    const parse_node_t &header, const parse_node_t &contents) {
-    assert(header.type == symbol_begin_header);
-    assert(contents.type == symbol_job_list);
-
+    tnode_t<g::begin_header> header, tnode_t<g::job_list> contents) {
     // Basic begin/end block. Push a scope block, run jobs, pop it
     scope_block_t *sb = parser->push_block<scope_block_t>(BEGIN);
     parse_execution_result_t ret = run_job_list(contents, sb);
diff --git a/src/parse_execution.h b/src/parse_execution.h
index 5ef894d03..ea0ce0791 100644
--- a/src/parse_execution.h
+++ b/src/parse_execution.h
@@ -103,8 +103,8 @@ class parse_execution_context_t {
                                                  tnode_t<grammar::job_list> contents);
     parse_execution_result_t run_function_statement(tnode_t<grammar::function_header> header,
                                                     tnode_t<grammar::end_command> block_end);
-    parse_execution_result_t run_begin_statement(const parse_node_t &header,
-                                                 const parse_node_t &contents);
+    parse_execution_result_t run_begin_statement(tnode_t<grammar::begin_header> header,
+                                                 tnode_t<grammar::job_list> contents);
 
     enum globspec_t { failglob, nullglob };
     parse_execution_result_t determine_arguments(const parse_node_t &parent,