diff --git a/Include/pymem.h b/Include/pymem.h
index 10b5bea..2c239df 100644
--- a/Include/pymem.h
+++ b/Include/pymem.h
@@ -72,9 +72,9 @@
 /* Returns NULL to indicate error if a negative size or size larger than
    Py_ssize_t can represent is supplied.  Helps prevents security holes. */
 #define PyMem_MALLOC(n)		((size_t)(n) > (size_t)PY_SSIZE_T_MAX ? NULL \
-				: malloc((n) ? (n) : 1))
+				: malloc(((n) != 0) ? (n) : 1))
 #define PyMem_REALLOC(p, n)	((size_t)(n) > (size_t)PY_SSIZE_T_MAX  ? NULL \
-				: realloc((p), (n) ? (n) : 1))
+				: realloc((p), ((n) != 0) ? (n) : 1))
 #define PyMem_FREE		free
 
 #endif	/* PYMALLOC_DEBUG */