diff --git a/gdbsupport/enum-flags.h b/gdbsupport/enum-flags.h
index 440ffe09734..947d4773052 100644
--- a/gdbsupport/enum-flags.h
+++ b/gdbsupport/enum-flags.h
@@ -91,9 +91,12 @@ template<> struct integer_for_size<8, 1> { typedef int64_t type; };
 template<typename T>
 struct enum_underlying_type
 {
+  DIAGNOSTIC_PUSH
+  DIAGNOSTIC_IGNORE_ENUM_CONSTEXPR_CONVERSION
   typedef typename
     integer_for_size<sizeof (T), static_cast<bool>(T (-1) < T (0))>::type
     type;
+  DIAGNOSTIC_POP
 };
 
 namespace enum_flags_detail
diff --git a/include/diagnostics.h b/include/diagnostics.h
index 3a75f4e2719..c164e7bd9f4 100644
--- a/include/diagnostics.h
+++ b/include/diagnostics.h
@@ -76,6 +76,11 @@
 # define DIAGNOSTIC_ERROR_SWITCH \
   DIAGNOSTIC_ERROR ("-Wswitch")
 
+# if __has_warning ("-Wenum-constexpr-conversion")
+#  define DIAGNOSTIC_IGNORE_ENUM_CONSTEXPR_CONVERSION \
+   DIAGNOSTIC_IGNORE ("-Wenum-constexpr-conversion")
+# endif
+
 #elif defined (__GNUC__) /* GCC */
 
 # define DIAGNOSTIC_IGNORE_DEPRECATED_DECLARATIONS \
@@ -155,4 +160,8 @@
 # define DIAGNOSTIC_ERROR_SWITCH
 #endif
 
+#ifndef DIAGNOSTIC_IGNORE_ENUM_CONSTEXPR_CONVERSION
+# define DIAGNOSTIC_IGNORE_ENUM_CONSTEXPR_CONVERSION
+#endif
+
 #endif /* DIAGNOSTICS_H */