diff --git a/packages/PLStream/pl-dtoa.c b/packages/PLStream/pl-dtoa.c
index c455d8d63..72077f487 100755
--- a/packages/PLStream/pl-dtoa.c
+++ b/packages/PLStream/pl-dtoa.c
@@ -30,7 +30,7 @@
 #define MALLOC PL_malloc
 #define FREE PL_free
 
-#if defined(_REENTRANT)||defined(__YAP_PROLOG__)
+#if defined(_REENTRANT)
 #define Long int			/* 32-bits */
 #define MULTIPLE_THREADS
 
@@ -56,6 +56,8 @@ FREE_DTOA_LOCK(int n)
     pthread_mutex_unlock(&mutex_1);
 }
 
+#elif defined(__YAP_PROLOG__)
+#define Long int			/* 32-bits */
 #endif /*MULTIPLE_THREADS*/
 
 #include "dtoa.c"