diff --git a/gcc/testsuite/gnat.dg/nan_max.adb b/gcc/testsuite/gnat.dg/nan_max.adb
new file mode 100644
index 00000000000..a2cac30f5e8
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/nan_max.adb
@@ -0,0 +1,30 @@
+-- { dg-do run }
+
+procedure Nan_Max is
+
+   function NaN return Long_Float is
+      Zero : Long_Float := 0.0;
+   begin
+      return Zero / Zero;
+   end;
+
+   Z : Long_Float := 1.0;
+   N : Long_Float := NaN;
+
+begin
+   if Long_Float'Max (N, Z) /= Z then
+      raise Program_Error;
+   end if;
+
+   if Long_Float'Max (Z, N) /= Z then
+      raise Program_Error;
+   end if;
+
+   if Long_Float'Max (NaN, Z) /= Z then
+      raise Program_Error;
+   end if;
+
+   if Long_Float'Max (Z, NaN) /= Z then
+      raise Program_Error;
+   end if;
+end;