diff --git a/usr.bin/xlint/lint1/param.h b/usr.bin/xlint/lint1/param.h
index 1e1b81eff481..0f9ca6800416 100644
--- a/usr.bin/xlint/lint1/param.h
+++ b/usr.bin/xlint/lint1/param.h
@@ -92,6 +92,9 @@
 #elif __vax__
 #define PTRDIFF_IS_LONG         0
 #define SIZEOF_IS_ULONG         0
+#elif __arm__
+#define PTRDIFF_IS_LONG		0
+#define SIZEOF_IS_ULONG		0
 #else
 #error unknown machine type
 #endif