diff --git a/gcc/ada/exp_ch7.adb b/gcc/ada/exp_ch7.adb
--- a/gcc/ada/exp_ch7.adb
+++ b/gcc/ada/exp_ch7.adb
@@ -5876,16 +5876,20 @@ package body Exp_Ch7 is
       --  This is done only for non-generic packages
 
       if Ekind (Spec_Id) = E_Package then
-         Push_Scope (Spec_Id);
-
-         --  Build dispatch tables of library level tagged types
+         --  Build dispatch tables of library-level tagged types for bodies
+         --  that are not compilation units (see Analyze_Compilation_Unit),
+         --  except for instances because they have no N_Compilation_Unit.
 
          if Tagged_Type_Expansion
            and then Is_Library_Level_Entity (Spec_Id)
+           and then (not Is_Compilation_Unit (Spec_Id)
+                      or else Is_Generic_Instance (Spec_Id))
          then
             Build_Static_Dispatch_Tables (N);
          end if;
 
+         Push_Scope (Spec_Id);
+
          Expand_CUDA_Package (N);
 
          Build_Task_Activation_Call (N);
@@ -6035,12 +6039,13 @@ package body Exp_Ch7 is
          Pop_Scope;
       end if;
 
-      --  Build dispatch tables of library-level tagged types
+      --  Build dispatch tables of library-level tagged types for instances
+      --  that are not compilation units (see Analyze_Compilation_Unit).
 
       if Tagged_Type_Expansion
-        and then (Is_Compilation_Unit (Id)
-                   or else (Is_Generic_Instance (Id)
-                             and then Is_Library_Level_Entity (Id)))
+        and then Is_Library_Level_Entity (Id)
+        and then Is_Generic_Instance (Id)
+        and then not Is_Compilation_Unit (Id)
       then
          Build_Static_Dispatch_Tables (N);
       end if;


diff --git a/gcc/ada/exp_disp.adb b/gcc/ada/exp_disp.adb
--- a/gcc/ada/exp_disp.adb
+++ b/gcc/ada/exp_disp.adb
@@ -524,12 +524,6 @@ package body Exp_Disp is
    --  Start of processing for Build_Static_Dispatch_Tables
 
    begin
-      if not Expander_Active
-        or else not Tagged_Type_Expansion
-      then
-         return;
-      end if;
-
       if Nkind (N) = N_Package_Declaration then
          declare
             Spec       : constant Node_Id := Specification (N);
@@ -553,8 +547,15 @@ package body Exp_Disp is
          end;
 
       else pragma Assert (Nkind (N) = N_Package_Body);
-         Target_List := Declarations (N);
-         Build_Dispatch_Tables (Target_List);
+         declare
+            Spec_Id : constant Entity_Id := Corresponding_Spec (N);
+
+         begin
+            Push_Scope (Spec_Id);
+            Target_List := Declarations (N);
+            Build_Dispatch_Tables (Target_List);
+            Pop_Scope;
+         end;
       end if;
    end Build_Static_Dispatch_Tables;
 


diff --git a/gcc/ada/sem_ch10.adb b/gcc/ada/sem_ch10.adb
--- a/gcc/ada/sem_ch10.adb
+++ b/gcc/ada/sem_ch10.adb
@@ -31,6 +31,7 @@ with Einfo;          use Einfo;
 with Einfo.Entities; use Einfo.Entities;
 with Einfo.Utils;    use Einfo.Utils;
 with Errout;         use Errout;
+with Exp_Disp;       use Exp_Disp;
 with Exp_Put_Image;
 with Exp_Util;       use Exp_Util;
 with Elists;         use Elists;
@@ -1000,6 +1001,22 @@ package body Sem_Ch10 is
          end if;
       end if;
 
+      --  Build dispatch tables of library-level tagged types only now because
+      --  the generation of distribution stubs above may create some of them.
+
+      if Expander_Active and then Tagged_Type_Expansion then
+         case Nkind (Unit_Node) is
+            when N_Package_Declaration | N_Package_Body =>
+               Build_Static_Dispatch_Tables (Unit_Node);
+
+            when N_Package_Instantiation =>
+               Build_Static_Dispatch_Tables (Instance_Spec (Unit_Node));
+
+            when others =>
+               null;
+         end case;
+      end if;
+
       --  Remove unit from visibility, so that environment is clean for the
       --  next compilation, which is either the main unit or some other unit
       --  in the context.