diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3690705de0d..050224151eb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-06  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* config/rs6000/rs6000.c (rs6000_option_override_internal): Don't
+	disable isel if it was not set explicitly.
+
 2017-11-06  James Bowman  <james.bowman@ftdichip.com>
 
 	* gcc/dwarf2out.c (modified_type_die): Retain ADDR_SPACE
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index c2712d9deb2..aacf3f12b32 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -4798,10 +4798,7 @@ rs6000_option_override_internal (bool global_init_p)
   /* For the E500 family of cores, reset the single/double FP flags to let us
      check that they remain constant across attributes or pragmas.  Also,
      clear a possible request for string instructions, not supported and which
-     we might have silently queried above for -Os. 
-
-     For other families, clear ISEL in case it was set implicitly.
-  */
+     we might have silently queried above for -Os.  */
 
   switch (rs6000_cpu)
     {
@@ -4811,19 +4808,12 @@ rs6000_option_override_internal (bool global_init_p)
     case PROCESSOR_PPCE500MC64:
     case PROCESSOR_PPCE5500:
     case PROCESSOR_PPCE6500:
-
       rs6000_single_float = 0;
       rs6000_double_float = 0;
-
       rs6000_isa_flags &= ~OPTION_MASK_STRING;
-
       break;
 
     default:
-
-      if (cpu_index >= 0 && !(rs6000_isa_flags_explicit & OPTION_MASK_ISEL))
-	rs6000_isa_flags &= ~OPTION_MASK_ISEL;
-
       break;
     }