diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -252,6 +252,10 @@
   the target of a procedure pointer assignment statement.
 * An explicit `INTERFACE` can declare the interface of a
   procedure pointer even if it is not a dummy argument.
+* A `NOPASS` type-bound procedure binding is required by C1529
+  to apply only to a scalar data-ref, but most compilers don't
+  enforce it and the constraint is not necessary for a correct
+  implementation.
 
 ### Extensions supported when enabled by options
 
diff --git a/flang/lib/Semantics/expression.cpp b/flang/lib/Semantics/expression.cpp
--- a/flang/lib/Semantics/expression.cpp
+++ b/flang/lib/Semantics/expression.cpp
@@ -2103,10 +2103,18 @@
         if (dataRef && !CheckDataRef(*dataRef)) {
           return std::nullopt;
         }
-        if (dataRef && dataRef->Rank() > 0 && sym->attrs().test(semantics::Attr::NOPASS)) {
-          // C1529 seems unnecessary and most compilers don't enforce it.
-          Say(sc.component.source,
-            "Base of procedure component reference should be scalar when NOPASS component or binding '%s' is referenced"_port_en_US, sc.component.source);
+        if (dataRef && dataRef->Rank() > 0) {
+          if (sym->has<semantics::ProcBindingDetails>() &&
+              sym->attrs().test(semantics::Attr::NOPASS)) {
+            // C1529 seems unnecessary and most compilers don't enforce it.
+            AttachDeclaration(
+                Say(sc.component.source,
+                    "Base of NOPASS type-bound procedure reference should be scalar"_port_en_US),
+                *sym);
+          } else if (IsProcedurePointer(*sym)) { // C919
+            Say(sc.component.source,
+                "Base of procedure component reference must be scalar"_err_en_US);
+          }
         }
         if (const Symbol *resolution{
                 GetBindingResolution(dtExpr->GetType(), *sym)}) {
diff --git a/flang/test/Semantics/bindings01.f90 b/flang/test/Semantics/bindings01.f90
--- a/flang/test/Semantics/bindings01.f90
+++ b/flang/test/Semantics/bindings01.f90
@@ -215,6 +215,24 @@
   end subroutine
 end module m7
 
+module m8 ! C1529 - warning only
+  type t
+    procedure(mysubr), pointer, nopass :: pp
+   contains
+    procedure, nopass :: tbp => mysubr
+  end type
+ contains
+  subroutine mysubr
+  end subroutine
+  subroutine test
+    type(t) a(2)
+    !PORTABILITY: Base of NOPASS type-bound procedure reference should be scalar
+    call a%tbp
+    !ERROR: Base of procedure component reference must be scalar
+    call a%pp
+  end subroutine
+end module
+
 program test
   use m1
   type,extends(t) :: t2