1 files changed, 1 insertions, 1 deletions
diff --git a/vm_core.h b/vm_core.h
index 9b72839bd1..a835e23005 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -510,7 +510,7 @@ VALUE rb_iseq_compile_with_option(VALUE src, VALUE file, VALUE filepath, VALUE l
 VALUE rb_iseq_disasm(VALUE self);
 int rb_iseq_disasm_insn(VALUE str, VALUE *iseqval, size_t pos, rb_iseq_t *iseq, VALUE child);
 const char *ruby_node_name(int node);
-int rb_iseq_first_lineno(rb_iseq_t *iseq);
+int rb_iseq_first_lineno(const rb_iseq_t *iseq);
 
 RUBY_EXTERN VALUE rb_cISeq;
 RUBY_EXTERN VALUE rb_cRubyVM;