diff --git a/gcc/config/rs6000/rs6000-c.c b/gcc/config/rs6000/rs6000-c.c
index f5982907e907dd850ef39221b6f1729a14b4911d..cc1e997524e3b01f9dc65744f087b2284622e229 100644
--- a/gcc/config/rs6000/rs6000-c.c
+++ b/gcc/config/rs6000/rs6000-c.c
@@ -597,6 +597,9 @@ rs6000_target_modify_macros (bool define_p, HOST_WIDE_INT flags,
   /* Tell the user if we support the MMA instructions.  */
   if ((flags & OPTION_MASK_MMA) != 0)
     rs6000_define_or_undefine_macro (define_p, "__MMA__");
+  /* Whether pc-relative code is being generated.  */
+  if ((flags & OPTION_MASK_PCREL) != 0)
+    rs6000_define_or_undefine_macro (define_p, "__PCREL__");
 }
 
 void