diff --git a/src/bits.h b/src/bits.h
index 1995390..68f0af2 100644
--- a/src/bits.h
+++ b/src/bits.h
@@ -30,6 +30,11 @@
 ERROR_64_BYTES_WORDSIZE_ONLY
 #endif
 
+typedef int64_t  s64;
+typedef int32_t  s32;
+typedef int16_t  s16;
+typedef int8_t   s8;
+
 typedef uint64_t u64;
 typedef uint32_t u32;
 typedef uint16_t u16;
diff --git a/src/chessdefs.h b/src/chessdefs.h
index 53e49b8..5d612f6 100644
--- a/src/chessdefs.h
+++ b/src/chessdefs.h
@@ -82,12 +82,12 @@ typedef unsigned char castle_t;
 
 /* bitboard
  */
-typedef uint64_t bitboard_t;
+typedef u64 bitboard_t;
 
 
 /* eval type
  */
-typedef int64_t eval_t;
+typedef u64 eval_t;
 
 /* forward typedefs
  */
diff --git a/src/debug.c b/src/debug.c
index 1eda994..2bfaea1 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -19,17 +19,17 @@
 #define NANOSEC  1000000000                       /* nano sec in sec */
 #define MILLISEC 1000000                          /* milli sec in sec */
 
-static int64_t timer_start;                       /* in nanosecond */
-static uint32_t debug_level=0;
+static s64 timer_start;                           /* in nanosecond */
+static u32 debug_level=0;
 
-void debug_level_set(uint32_t level)
+void debug_level_set(u32 level)
 {
     debug_level = level;;
 
     log(0, "debug level set to %u\n", level);
 }
 
-void debug_init(uint32_t level)
+void debug_init(u32 level)
 {
     struct timespec timer;
 
@@ -43,7 +43,7 @@ void debug_init(uint32_t level)
     log(0, "timer started.\n");
 }
 
-inline static int64_t timer_elapsed()
+inline static s64 timer_elapsed()
 {
     struct timespec timer;
 
@@ -58,8 +58,8 @@ inline static int64_t timer_elapsed()
  * @src       : source file/func name (or NULL)
  * @line      : line number
  */
-void debug(uint32_t level, bool timestamp, uint32_t indent, const char *src,
-           uint32_t line, const char *fmt, ...)
+void debug(u32 level, bool timestamp, u32 indent, const char *src,
+           u32 line, const char *fmt, ...)
 {
     if (level > debug_level)
         return;
@@ -70,7 +70,7 @@ void debug(uint32_t level, bool timestamp, uint32_t indent, const char *src,
         printf("%*s", 2*(indent-1), "");
 
     if (timestamp) {
-        int64_t diff = timer_elapsed();
+        s64 diff = timer_elapsed();
         printf("%ld.%03ld ", diff/NANOSEC, (diff/1000000)%1000);
         printf("%010ld ", diff);
     }
diff --git a/src/debug.h b/src/debug.h
index 6bcdde5..06514fe 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -17,11 +17,13 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-void debug_init(uint32_t level);
-void debug_level_set(uint32_t level);
-void debug_devel_set(uint32_t level);
-void debug(uint32_t level, bool timestamp, uint32_t indent,
-           const char *src, uint32_t line, const char *, ...);
+#include "bits.h"
+
+void debug_init(u32 level);
+void debug_level_set(u32 level);
+void debug_devel_set(u32 level);
+void debug(u32 level, bool timestamp, u32 indent,
+           const char *src, u32 line, const char *, ...);
 
 #ifdef DEBUG
 
diff --git a/src/piece.h b/src/piece.h
index 096d7e3..e9682fd 100644
--- a/src/piece.h
+++ b/src/piece.h
@@ -34,7 +34,7 @@ typedef struct piece_list_s {
     piece_t piece;
     square_t square;
     short castle;
-    int64_t value;
+    s64 value;
     struct list_head list;
 } piece_list_t;
 
@@ -46,7 +46,7 @@ extern struct piece_details {
     char *symbol_w;
     char *symbol_b;                               /* used for game notation */
     char *name;
-    int64_t value;
+    s64  value;
 } piece_details[];
 
 #define P_NAME(p)      piece_details[E_PIECE(p)].name
diff --git a/src/pool.c b/src/pool.c
index 30ae7af..7ab0265 100644
--- a/src/pool.c
+++ b/src/pool.c
@@ -23,6 +23,7 @@
 #include "list.h"
 #include "pool.h"
 #include "debug.h"
+#include "bits.h"
 
 void pool_stats(pool_t *pool)
 {
@@ -35,7 +36,7 @@ void pool_stats(pool_t *pool)
     }
 }
 
-pool_t *pool_init(const char *name, uint32_t growsize, size_t eltsize)
+pool_t *pool_init(const char *name, u32 growsize, size_t eltsize)
 {
     pool_t *pool;
 
@@ -57,7 +58,7 @@ pool_t *pool_init(const char *name, uint32_t growsize, size_t eltsize)
     return pool;
 }
 
-static uint32_t _pool_add(pool_t *pool, struct list_head *elt)
+static u32 _pool_add(pool_t *pool, struct list_head *elt)
 {
 #   ifdef DEBUG_POOL
     log_f(10, "pool=%p &head=%p elt=%p off1=%lu off2=%lu\n",
@@ -72,7 +73,7 @@ static uint32_t _pool_add(pool_t *pool, struct list_head *elt)
     return ++pool->available;
 }
 
-uint32_t pool_add(pool_t *pool, void *elt)
+u32 pool_add(pool_t *pool, void *elt)
 {
     return _pool_add(pool, elt);
 }
@@ -92,7 +93,7 @@ void *pool_get(pool_t *pool)
     if (!pool->available) {
         void *alloc = malloc(pool->eltsize * pool->growsize);
         void *cur;
-        uint32_t i;
+        u32 i;
 #       ifdef DEBUG_POOL
         log_f(1, "[%s]: growing pool from %u to %u elements.\n",
                pool->name,
@@ -125,7 +126,7 @@ void *pool_get(pool_t *pool)
 
 #ifdef BIN_pool
 struct d {
-    uint16_t data1;
+    u16 data1;
     char c;
     struct list_head list;
 };
@@ -137,7 +138,7 @@ int main(int ac, char**av)
     pool_t *pool;
     int total;
     int action=0;
-    uint16_t icur=0;
+    u16 icur=0;
     char ccur='z';
     struct d *elt;
 
diff --git a/src/pool.h b/src/pool.h
index fb144aa..37fd667 100644
--- a/src/pool.h
+++ b/src/pool.h
@@ -17,19 +17,20 @@
 #include <stdint.h>
 #include <stddef.h>
 #include "list.h"
+#include "bits.h"
 
 typedef struct {
     char *name;
-    uint32_t available;
-    uint32_t allocated;
-    uint32_t growsize;
+    u32 available;
+    u32 allocated;
+    u32 growsize;
     size_t eltsize;
     struct list_head head;
 } pool_t;
 
 void pool_stats(pool_t *pool);
-pool_t *pool_init(const char *name, uint32_t grow, size_t size);
+pool_t *pool_init(const char *name, u32 grow, size_t size);
 void *pool_get(pool_t *pool);
-uint32_t pool_add(pool_t *pool, void *elt);
+u32 pool_add(pool_t *pool, void *elt);
 
 #endif