Index: flang/lib/Semantics/check-declarations.cpp
===================================================================
--- flang/lib/Semantics/check-declarations.cpp
+++ flang/lib/Semantics/check-declarations.cpp
@@ -351,6 +351,10 @@
           "A dummy argument may not have the SAVE attribute"_err_en_US);
     }
   } else if (IsFunctionResult(symbol)) {
+    if (IsNamedConstant(symbol)) {
+      messages_.Say(
+          "A function result may not also be a named constant"_err_en_US);
+    }
     if (!symbol.test(Symbol::Flag::InDataStmt) /*caught elsewhere*/ &&
         IsSaved(symbol)) {
       messages_.Say(
Index: flang/test/Semantics/declarations01.f90
===================================================================
--- /dev/null
+++ flang/test/Semantics/declarations01.f90
@@ -0,0 +1,8 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+! test named constant declarations
+
+function f1() result(x)
+  !ERROR: A function result may not also be a named constant
+  integer, parameter :: x = 1
+end
+