Index: gcc/fortran/interface.c
===================================================================
--- gcc/fortran/interface.c	(revision 198007)
+++ gcc/fortran/interface.c	(working copy)
@@ -1184,9 +1184,16 @@ check_result_characteristics (gfc_symbol *s1, gfc_
 {
   gfc_symbol *r1, *r2;
 
-  r1 = s1->result ? s1->result : s1;
-  r2 = s2->result ? s2->result : s2;
+  if (s1->ts.interface && s1->ts.interface->result)
+    r1 = s1->ts.interface->result;
+  else
+    r1 = s1->result ? s1->result : s1;
 
+  if (s2->ts.interface && s2->ts.interface->result)
+    r2 = s2->ts.interface->result;
+  else
+    r2 = s2->result ? s2->result : s2;
+
   if (r1->ts.type == BT_UNKNOWN)
     return true;