diff --git a/mingw-w64-crt/string/memchr.c b/mingw-w64-crt/string/memchr.c
index e115afc..f15f2aa 100644
--- a/mingw-w64-crt/string/memchr.c
+++ b/mingw-w64-crt/string/memchr.c
@@ -29,7 +29,7 @@
 #define ALIGN (sizeof(size_t)-1)
 #define ONES ((size_t)-1/UCHAR_MAX)
 #define HIGHS (ONES * (UCHAR_MAX/2+1))
-#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
+#define HASZERO(x) ( ((x)-ONES) & ~(x) & HIGHS )
 
 void *memchr(const void *src, int c, size_t n)
 {
diff --git a/mingw-w64-crt/string/strchrnul.c b/mingw-w64-crt/string/strchrnul.c
index 889446a..2aa9c18 100644
--- a/mingw-w64-crt/string/strchrnul.c
+++ b/mingw-w64-crt/string/strchrnul.c
@@ -28,7 +28,7 @@
 #define ALIGN (sizeof(size_t))
 #define ONES ((size_t)-1/UCHAR_MAX)
 #define HIGHS (ONES * (UCHAR_MAX/2+1))
-#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
+#define HASZERO(x) ( ((x)-ONES) & ~(x) & HIGHS )
 
 char *__strchrnul(const char *s, int c);