diff --git a/include/picrin/macro.h b/include/picrin/macro.h
index 5dcf2c5d..1dd6cd81 100644
--- a/include/picrin/macro.h
+++ b/include/picrin/macro.h
@@ -17,7 +17,8 @@ struct pic_syntax {
     PIC_STX_QUOTE,
     PIC_STX_LAMBDA,
     PIC_STX_IF,
-    PIC_STX_BEGIN
+    PIC_STX_BEGIN,
+    PIC_STX_DEFMACRO
   } kind;
   pic_sym sym;
 };
diff --git a/src/state.c b/src/state.c
index fe6c7695..68d9c891 100644
--- a/src/state.c
+++ b/src/state.c
@@ -132,6 +132,7 @@ pic_open(int argc, char *argv[], char **envp)
   register_core_syntax(pic, PIC_STX_LAMBDA, "lambda");
   register_core_syntax(pic, PIC_STX_IF, "if");
   register_core_syntax(pic, PIC_STX_BEGIN, "begin");
+  register_core_syntax(pic, PIC_STX_DEFMACRO, "define-macro");
   pic_gc_arena_restore(pic, ai);
 
   pic_init_core(pic);