diff --git a/ext/colopl_bc_php70.c b/ext/colopl_bc_php70.c
index 928722d..937ddd1 100644
--- a/ext/colopl_bc_php70.c
+++ b/ext/colopl_bc_php70.c
@@ -142,6 +142,15 @@ PHP_FUNCTION(Colopl_ColoplBc_Php70_getrandmax)
 
 /* mt_rand.c */
 
+#define N				COLOPL_BC_MT_N			/* length of state vector */
+#define M				(397)					/* a period parameter */
+#define hiBit(u)		((u) & 0x80000000U)		/* mask all but highest   bit of u */
+#define loBit(u)		((u) & 0x00000001U)		/* mask all but lowest    bit of u */
+#define loBits(u)		((u) & 0x7FFFFFFFU)		/* mask     the highest   bit of u */
+#define mixBits(u, v)	(hiBit(u)|loBits(v))	/* move hi bit of u to hi bit of v */
+
+#define twist(m,u,v)	(m ^ (mixBits(u,v)>>1) ^ ((uint32_t)(-(uint32_t)(loBit(u))) & 0x9908b0dfU))
+
 static inline void mt_initialize(uint32_t seed, uint32_t *state)
 {
 	register uint32_t *s = state;
diff --git a/ext/php_colopl_bc.h b/ext/php_colopl_bc.h
index 927d406..dabda2f 100644
--- a/ext/php_colopl_bc.h
+++ b/ext/php_colopl_bc.h
@@ -48,7 +48,7 @@ ZEND_BEGIN_MODULE_GLOBALS(colopl_bc)
 	bool rand_is_seeded;
 	bool mt_rand_is_seeded;
 	uint32_t rand_seed;
-	uint32_t mt_state[N+1];
+	uint32_t mt_state[COLOPL_BC_MT_N+1];
 	uint32_t *mt_next;
 	int mt_left;
 	int gnurandom_r[344];
diff --git a/ext/php_colopl_bc_php70.h b/ext/php_colopl_bc_php70.h
index 08c493e..56a70e5 100644
--- a/ext/php_colopl_bc_php70.h
+++ b/ext/php_colopl_bc_php70.h
@@ -113,14 +113,7 @@ PHPAPI zend_long php_colopl_bc_rand(void);
 
 #define PHP_COLOPL_BC_MT_RAND_MAX ((zend_long) (0x7FFFFFFF)) /* (1<<31) - 1 */
 
-#define N				(624)					/* length of state vector */
-#define M				(397)					/* a period parameter */
-#define hiBit(u)		((u) & 0x80000000U)		/* mask all but highest   bit of u */
-#define loBit(u)		((u) & 0x00000001U)		/* mask all but lowest    bit of u */
-#define loBits(u)		((u) & 0x7FFFFFFFU)		/* mask     the highest   bit of u */
-#define mixBits(u, v)	(hiBit(u)|loBits(v))	/* move hi bit of u to hi bit of v */
-
-#define twist(m,u,v)	(m ^ (mixBits(u,v)>>1) ^ ((uint32_t)(-(uint32_t)(loBit(u))) & 0x9908b0dfU))
+#define COLOPL_BC_MT_N	(624)
 
 PHPAPI void php_colopl_bc_mt_srand(uint32_t seed);
 PHPAPI uint32_t php_colopl_bc_mt_rand(void);