diff --git a/newlib/libc/include/sys/reent.h b/newlib/libc/include/sys/reent.h
index fa9c6cf82..90f848180 100644
--- a/newlib/libc/include/sys/reent.h
+++ b/newlib/libc/include/sys/reent.h
@@ -763,6 +763,8 @@ extern struct _reent _impure_data __ATTRIBUTE_IMPURE_DATA__;
 # define _REENT _impure_ptr
 #endif /* __SINGLE_THREAD__ || !__DYNAMIC_REENT__ */
 
+#define _REENT_IS_NULL(_ptr) ((_ptr) == NULL)
+
 #define _GLOBAL_REENT (&_impure_data)
 
 /* This value is used in stdlib/misc.c.  reent/reent.c has to know it
diff --git a/newlib/libc/machine/spu/c99ppe.h b/newlib/libc/machine/spu/c99ppe.h
index 7b3fcb6b7..6e03d2cb9 100644
--- a/newlib/libc/machine/spu/c99ppe.h
+++ b/newlib/libc/machine/spu/c99ppe.h
@@ -104,6 +104,12 @@ FILE  *__sfp (struct _reent *);
 #define __sfp_free(fp) ( (fp)->_fp = 0 )
 
 #define CHECK_INIT(ptr) \
-  do { if ((ptr) && !_REENT_CLEANUP(ptr)) __sinit (ptr); } while (0)
+  do						\
+    {						\
+      if (!_REENT_IS_NULL(ptr) &&		\
+	  !_REENT_CLEANUP(ptr))			\
+	__sinit (ptr);				\
+    }						\
+  while (0)
 #define CHECK_STR_INIT(ptr) /* currently, do nothing */
 #endif /* __ASSEMBLER__ */
diff --git a/newlib/libc/stdio/local.h b/newlib/libc/stdio/local.h
index 24eaff351..b34c7c9d8 100644
--- a/newlib/libc/stdio/local.h
+++ b/newlib/libc/stdio/local.h
@@ -197,7 +197,8 @@ extern _READ_WRITE_RETURN_TYPE __swrite64 (struct _reent *, void *,
   do								\
     {								\
       struct _reent *_check_init_ptr = (ptr);			\
-      if ((_check_init_ptr) && !_REENT_CLEANUP(_check_init_ptr))\
+      if (!_REENT_IS_NULL(_check_init_ptr) &&			\
+	  !_REENT_CLEANUP(_check_init_ptr))			\
 	__sinit (_check_init_ptr);				\
     }								\
   while (0)
diff --git a/newlib/libc/sys/arm/syscalls.c b/newlib/libc/sys/arm/syscalls.c
index 325c0117f..dd49ca061 100644
--- a/newlib/libc/sys/arm/syscalls.c
+++ b/newlib/libc/sys/arm/syscalls.c
@@ -60,7 +60,8 @@ extern void   __sinit (struct _reent *);
 #define CHECK_INIT(ptr) \
   do						\
     {						\
-      if ((ptr) && !_REENT_CLEANUP(ptr))	\
+      if (!_REENT_IS_NULL(ptr) &&		\
+	  !_REENT_CLEANUP(ptr))			\
 	__sinit (ptr);				\
     }						\
   while (0)