diff --git a/configure.ac b/configure.ac
index c92e047..9e9a0b4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -95,6 +95,7 @@
 AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_UINT8_T
+AC_CHECK_TYPES([ptrdiff_t], [], [exit 1])
 
 AC_STRUCT_TM