diff --git a/ext/ripper/eventids2.c b/ext/ripper/eventids2.c
index ac54955857..439663f0fd 100644
--- a/ext/ripper/eventids2.c
+++ b/ext/ripper/eventids2.c
@@ -65,6 +65,8 @@ static ripper_scanner_ids_t ripper_scanner_ids;
 
 #include "eventids2table.c"
 
+STATIC_ASSERT(eventids2_table_size, RIPPER_EVENTIDS2_TABLE_SIZE == sizeof(ripper_scanner_ids)/sizeof(ID));
+
 void
 ripper_init_eventids2(void)
 {
diff --git a/ext/ripper/tools/generate.rb b/ext/ripper/tools/generate.rb
index bb64d2fe8b..c44b4ba325 100644
--- a/ext/ripper/tools/generate.rb
+++ b/ext/ripper/tools/generate.rb
@@ -136,6 +136,8 @@ def generate_eventids2_table(ids)
     buf << %Q[    rb_hash_aset(h, intern_sym("#{id}"), INT2FIX(1));\n]
   end
   buf << %Q[}\n]
+  buf << %Q[\n]
+  buf << %Q[#define RIPPER_EVENTIDS2_TABLE_SIZE #{ids.size}\n]
   buf
 end