diff --git a/lib/getdelim.c b/lib/getdelim.c
index 42cac8f55..a131b0c63 100644
--- a/lib/getdelim.c
+++ b/lib/getdelim.c
@@ -29,6 +29,9 @@
 #include <stdlib.h>
 #include <errno.h>
 
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
 #ifndef SSIZE_MAX
 # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
 #endif