diff --git a/src/config.h b/src/config.h
deleted file mode 100644
index 8387f4fd..00000000
--- a/src/config.h
+++ /dev/null
@@ -1,7 +0,0 @@
-/* configurations for Picrin interpreter */
-
-#define PIC_ARENA_SIZE (8 * 1024)
-
-#define PIC_HEAP_PAGE_SIZE (2 * 1024 * 1024)
-
-#define PIC_SYM_POOL_SIZE (2 * 1024)
diff --git a/src/main.c b/src/main.c
index 7418e61d..11b79347 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,7 +2,9 @@
  * See Copyright Notice in picrin.h
  */
 
-#include "config.h"
+#define PIC_ARENA_SIZE (8 * 1024)
+#define PIC_HEAP_PAGE_SIZE (2 * 1024 * 1024)
+#define PIC_SYM_POOL_SIZE (2 * 1024)
 
 #include "picrin.h"
 #include "picrin/pair.h"