diff --git a/include/picrin/config.h b/include/picrin/config.h
index 76c30066..889e268b 100644
--- a/include/picrin/config.h
+++ b/include/picrin/config.h
@@ -58,11 +58,11 @@
 #endif
 
 #ifndef PIC_ARENA_SIZE
-# define PIC_ARENA_SIZE 1000
+# define PIC_ARENA_SIZE (8 * 1024)
 #endif
 
 #ifndef PIC_HEAP_PAGE_SIZE
-# define PIC_HEAP_PAGE_SIZE 10000
+# define PIC_HEAP_PAGE_SIZE (2 * 1024 * 1024)
 #endif
 
 #ifndef PIC_STACK_SIZE
@@ -74,7 +74,7 @@
 #endif
 
 #ifndef PIC_SYM_POOL_SIZE
-# define PIC_SYM_POOL_SIZE 128
+# define PIC_SYM_POOL_SIZE (2 * 1024)
 #endif
 
 #ifndef PIC_IREP_SIZE