diff --git a/src/include/c.h b/src/include/c.h
index 58b75440c13..47c5e8db112 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -295,6 +295,10 @@ typedef unsigned long long int uint64;
 #define UINT64CONST(x) ((uint64) x)
 #endif
 
+/* Max value of size_t might be missing if we don't have stdint.h */
+#ifndef SIZE_MAX
+#define SIZE_MAX ((size_t) -1)
+#endif
 
 /* Select timestamp representation (float8 or int64) */
 #ifdef USE_INTEGER_DATETIMES
diff --git a/src/timezone/private.h b/src/timezone/private.h
index f031b17b7ef..f78053660e8 100644
--- a/src/timezone/private.h
+++ b/src/timezone/private.h
@@ -48,10 +48,6 @@
 /* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
 #define is_digit(c) ((unsigned)(c) - '0' <= 9)
 
-#ifndef SIZE_MAX
-#define SIZE_MAX ((size_t) -1)
-#endif
-
 /*
  * SunOS 4.1.1 libraries lack remove.
  */