diff --git a/compiler/aoptobj.pas b/compiler/aoptobj.pas
index d8721e0848..47646f6927 100644
--- a/compiler/aoptobj.pas
+++ b/compiler/aoptobj.pas
@@ -127,7 +127,7 @@ Unit AoptObj;
         { can this instruction be removed? }
         CanBeRemoved: Boolean;
 
-        Constructor create;
+        Constructor create; reintroduce;
 
         { checks the whole sequence of which (so regs[which].StartMod and and  }
         { the next NrOfMods Tai objects) to see whether Reg is used somewhere, }
@@ -245,7 +245,7 @@ Unit AoptObj;
         { that has to be optimized and _LabelInfo a pointer to a       }
         { TLabelInfo record                                            }
         Constructor create(_AsmL: TAsmList; _BlockStart, _BlockEnd: Tai;
-                           _LabelInfo: PLabelInfo); virtual;
+                           _LabelInfo: PLabelInfo); virtual; reintroduce;
 
         { processor independent methods }
 
diff --git a/compiler/nflw.pas b/compiler/nflw.pas
index 4a85ea37d7..87773b5b26 100644
--- a/compiler/nflw.pas
+++ b/compiler/nflw.pas
@@ -71,7 +71,7 @@ interface
        end;
 
        twhilerepeatnode = class(tloopnode)
-          constructor create(l,r:Tnode;tab,cn:boolean);virtual;
+          constructor create(l,r:Tnode;tab,cn:boolean);virtual;reintroduce;
           function pass_typecheck:tnode;override;
           function pass_1 : tnode;override;
 {$ifdef state_tracking}
@@ -81,7 +81,7 @@ interface
        twhilerepeatnodeclass = class of twhilerepeatnode;
 
        tifnode = class(tloopnode)
-          constructor create(l,r,_t1 : tnode);virtual;
+          constructor create(l,r,_t1 : tnode);virtual;reintroduce;
           function pass_typecheck:tnode;override;
           function pass_1 : tnode;override;
        end;
@@ -93,7 +93,7 @@ interface
             number of executions }
           entrylabel : tnode;
           loopvar_notid:cardinal;
-          constructor create(l,r,_t1,_t2 : tnode;back : boolean);virtual;
+          constructor create(l,r,_t1,_t2 : tnode;back : boolean);virtual;reintroduce;
           procedure loop_var_access(not_type:Tnotification_flag;symbol:Tsym);
           function pass_typecheck:tnode;override;
           function pass_1 : tnode;override;
@@ -172,7 +172,7 @@ interface
        traisenodeclass = class of traisenode;
 
        ttryexceptnode = class(tloopnode)
-          constructor create(l,r,_t1 : tnode);virtual;
+          constructor create(l,r,_t1 : tnode);virtual;reintroduce;
           function pass_typecheck:tnode;override;
           function pass_1 : tnode;override;
        end;
@@ -180,7 +180,7 @@ interface
 
        ttryfinallynode = class(tloopnode)
           implicitframe : boolean;
-          constructor create(l,r:tnode);virtual;
+          constructor create(l,r:tnode);virtual;reintroduce;
           constructor create_implicit(l,r,_t1:tnode);virtual;
           function pass_typecheck:tnode;override;
           function pass_1 : tnode;override;
diff --git a/compiler/nopt.pas b/compiler/nopt.pas
index 6f1b35edb9..725b6bee53 100644
--- a/compiler/nopt.pas
+++ b/compiler/nopt.pas
@@ -35,7 +35,7 @@ type
 
   taddoptnode = class(taddnode)
      subnodetype: tsubnodetype;
-     constructor create(ts: tsubnodetype; l,r : tnode); virtual;
+     constructor create(ts: tsubnodetype; l,r : tnode); virtual; reintroduce;
      { pass_1 will be overridden by the separate subclasses    }
      { By default, pass_generate_code is the same as for addnode           }
      { Only if there's a processor specific implementation, it }
@@ -59,13 +59,13 @@ type
 
   { add a char to a shortstring }
   taddsstringcharoptnode = class(taddsstringoptnode)
-    constructor create(l,r : tnode); virtual;
+    constructor create(l,r : tnode); virtual; reintroduce;
   end;
   taddsstringcharoptnodeclass = class of taddsstringcharoptnode;
 
   { add a constant string to a short string }
   taddsstringcsstringoptnode = class(taddsstringoptnode)
-    constructor create(l,r : tnode); virtual;
+    constructor create(l,r : tnode); virtual; reintroduce;
     function pass_1: tnode; override;
   end;
   taddsstringcsstringoptnodeclass = class of taddsstringcsstringoptnode;
diff --git a/compiler/nset.pas b/compiler/nset.pas
index fc2c2f89ef..1227a7f0b2 100644
--- a/compiler/nset.pas
+++ b/compiler/nset.pas
@@ -59,7 +59,7 @@ interface
        tsetelementnodeclass = class of tsetelementnode;
 
        tinnode = class(tbinopnode)
-          constructor create(l,r : tnode);virtual;
+          constructor create(l,r : tnode);virtual;reintroduce;
           function pass_typecheck:tnode;override;
           function pass_1 : tnode;override;
        end;