diff --git a/sandbox/Makefile b/sandbox/Makefile
index 5c0c698..79d50b0 100644
--- a/sandbox/Makefile
+++ b/sandbox/Makefile
@@ -1,4 +1,4 @@
-SANDBOX_DIR_LIST := $(sort $(dir $(wildcard ./*/.)))
+SANDBOX_DIR_LIST := $(filter-out ./include/,$(sort $(dir $(wildcard ./*/.))))
 
 all:
 	@for prog in $(SANDBOX_DIR_LIST); do \
diff --git a/sandbox/include/socks/types.h b/sandbox/include/socks/types.h
new file mode 100644
index 0000000..d8a9c4b
--- /dev/null
+++ b/sandbox/include/socks/types.h
@@ -0,0 +1,8 @@
+#ifndef SOCKS_TYPES_H_
+#define SOCKS_TYPES_H_
+
+#include <stdint.h>
+
+typedef uintptr_t phys_addr_t;
+
+#endif
diff --git a/sandbox/memblock/memblock.h b/sandbox/memblock/memblock.h
index c0806c1..f6fbec2 100644
--- a/sandbox/memblock/memblock.h
+++ b/sandbox/memblock/memblock.h
@@ -3,7 +3,7 @@
 
 #include <stddef.h>
 #include <limits.h>
-#include <stdint.h>
+#include <socks/types.h>
 
 #define MEMBLOCK_INIT_MEMORY_REGION_COUNT 128
 #define MEMBLOCK_INIT_RESERVED_REGION_COUNT 128
@@ -37,9 +37,9 @@ typedef enum memblock_region_status {
 
 typedef struct memblock_region {
 	/* the address of the first byte that makes up the region */
-	uintptr_t base;
+	phys_addr_t base;
 	/* the address of the last byte that makes up the region */
-	size_t limit;
+	phys_addr_t limit;
 } memblock_region_t;
 
 typedef struct memblock_type {
@@ -56,21 +56,21 @@ typedef struct memblock {
 
 typedef struct memblock_iter {
 	memblock_index_t idx;
-	uintptr_t base;
-	size_t limit;
+	phys_addr_t base;
+	phys_addr_t limit;
 } memblock_iter_t;
 
 extern memblock_t memblock;
 
 extern int __next_mem_range(memblock_iter_t *it);
 
-extern int memblock_add(uintptr_t base, size_t size);
-extern int memblock_reserve(uintptr_t base, size_t size);
+extern int memblock_add(phys_addr_t base, size_t size);
+extern int memblock_reserve(phys_addr_t base, size_t size);
 
-extern uintptr_t memblock_alloc(size_t size);
+extern phys_addr_t memblock_alloc(size_t size);
 
 extern void __next_memory_region(memblock_iter_t *it, \
 		memblock_type_t *type_a, memblock_type_t *type_b,
-		uintptr_t start, uintptr_t end);
+		phys_addr_t start, phys_addr_t end);
 
 #endif
diff --git a/sandbox/sandbox-template.mk b/sandbox/sandbox-template.mk
index b600465..893cc88 100644
--- a/sandbox/sandbox-template.mk
+++ b/sandbox/sandbox-template.mk
@@ -3,7 +3,7 @@ BUILD_DIR := $(SANDBOX_BUILD_DIR)/$(SANDBOX_PROG_NAME)
 SRC := $(wildcard *.c)
 OBJ := $(addprefix $(BUILD_DIR)/,$(SRC:.c=.o))
 
-CFLAGS := -g
+CFLAGS := -g "-I$(SANDBOX_BASE_DIR)/include"
 
 $(BUILD_DIR)/$(SANDBOX_PROG_NAME): $(OBJ)
 	@mkdir -p $(@D)