diff --git a/ChangeLog.txt b/ChangeLog.txt
index 3c1c585bdf..efd3d4a601 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -7,6 +7,20 @@
    Entries may not always be in chronological/commit order.
    See license at the end of file. */
 
+2023-11-13 23:58 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * contrib/hbct/ctwin.c
+    ! typo in comment
+
+  * include/hbexprb.c
+  * include/hbexprop.h
+  * src/common/expropt2.c
+  * src/harbour.def
+    * moved code for reducing NOT expression to new separate function
+      hb_compExprReduceNot()
+    ; added comments to mark places for possible compiletime warnings when
+      incompatible types are used inside in logical expressions
+      (.AND. / .OR. / .NOT.)
+
 2023-11-12 16:40 UTC+0100 Phil Krylov (phil a t krylov.eu)
   * .github/workflows/linux-ci.yml
   * .github/workflows/macos-ci.yml
diff --git a/contrib/hbct/ctwin.c b/contrib/hbct/ctwin.c
index 570b02013e..269d8bf4cc 100644
--- a/contrib/hbct/ctwin.c
+++ b/contrib/hbct/ctwin.c
@@ -1947,7 +1947,7 @@ static HB_BOOL hb_ctw_gt_PutChar( PHB_GT pGT, int iRow, int iCol,
          iWindow = pCTW->pWindowMap[ lIndex ];
 #if 0
          /* When window with shadow is closed CT3 restores attributes
-          * which existed before shadow was displayed. In some application
+          * which existed before shadow was displayed. In an application
           * which switches to window 0 for pass-throw output it causes that
           * wrong attributes appears after this operation. In Harbour it's
           * fixed so such problem do not exist. Anyhow some code may switch
diff --git a/include/hbexprb.c b/include/hbexprb.c
index efda8c8279..413ad63f3b 100644
--- a/include/hbexprb.c
+++ b/include/hbexprb.c
@@ -3407,30 +3407,10 @@ static HB_EXPR_FUNC( hb_compExprUseNot )
    switch( iMessage )
    {
       case HB_EA_REDUCE:
-      {
-         PHB_EXPR pExpr;
-
          pSelf->value.asOperator.pLeft = HB_EXPR_USE( pSelf->value.asOperator.pLeft, HB_EA_REDUCE );
-         pExpr = pSelf->value.asOperator.pLeft;
-
-         if( pExpr->ExprType == HB_ET_LOGICAL )
-         {
-            pExpr->value.asLogical = ! pExpr->value.asLogical;
-            HB_COMP_EXPR_CLEAR( pSelf );
-            pSelf = pExpr;
-         }
-         else if( pExpr->ExprType == HB_EO_NOT && HB_SUPPORT_EXTOPT )
-         {
-            /* NOTE: This will not generate a runtime error if incompatible
-             * data type is used
-             */
-            pExpr->ExprType = HB_ET_NONE;  /* do not delete operator parameter - we are still using it */
-            pExpr = pExpr->value.asOperator.pLeft;
-            HB_COMP_EXPR_FREE( pSelf );
-            pSelf = pExpr;
-         }
+         pSelf = hb_compExprReduceNot( pSelf, HB_COMP_PARAM );
          break;
-      }
+
       case HB_EA_ARRAY_AT:
          HB_COMP_ERROR_TYPE( pSelf );
          break;
diff --git a/include/hbexprop.h b/include/hbexprop.h
index 5de924e660..727736931a 100644
--- a/include/hbexprop.h
+++ b/include/hbexprop.h
@@ -179,6 +179,7 @@ extern HB_EXPORT_INT PHB_EXPR hb_compExprReduceLT( PHB_EXPR pSelf, HB_COMP_DECL
 extern HB_EXPORT_INT PHB_EXPR hb_compExprReduceEQ( PHB_EXPR pSelf, HB_COMP_DECL );
 extern HB_EXPORT_INT PHB_EXPR hb_compExprReduceAnd( PHB_EXPR pSelf, HB_COMP_DECL );
 extern HB_EXPORT_INT PHB_EXPR hb_compExprReduceOr( PHB_EXPR pSelf, HB_COMP_DECL );
+extern HB_EXPORT_INT PHB_EXPR hb_compExprReduceNot( PHB_EXPR pSelf, HB_COMP_DECL );
 extern HB_EXPORT_INT PHB_EXPR hb_compExprReduceIIF( PHB_EXPR, HB_COMP_DECL );
 
 extern HB_EXPORT_INT HB_BOOL hb_compExprReduceAT( PHB_EXPR, HB_COMP_DECL );
diff --git a/src/common/expropt2.c b/src/common/expropt2.c
index 240f0e9905..9865594722 100644
--- a/src/common/expropt2.c
+++ b/src/common/expropt2.c
@@ -967,6 +967,11 @@ PHB_EXPR hb_compExprReduceNegate( PHB_EXPR pSelf, HB_COMP_DECL )
       HB_COMP_EXPR_FREE( pSelf );
       pSelf = pExpr;
    }
+   /* TODO: add checking of incompatible types
+      else
+      {
+      }
+    */
 
    return pSelf;
 }
@@ -1798,6 +1803,11 @@ PHB_EXPR hb_compExprReduceAnd( PHB_EXPR pSelf, HB_COMP_DECL )
          pSelf->value.asLogical = HB_FALSE;
       }
    }
+   /* TODO: add checking of incompatible types
+      else
+      {
+      }
+    */
    return pSelf;
 }
 
@@ -1866,6 +1876,42 @@ PHB_EXPR hb_compExprReduceOr( PHB_EXPR pSelf, HB_COMP_DECL )
          pSelf = pLeft;
       }
    }
+   /* TODO: add checking of incompatible types
+      else
+      {
+      }
+    */
+   return pSelf;
+}
+
+PHB_EXPR hb_compExprReduceNot( PHB_EXPR pSelf, HB_COMP_DECL )
+{
+   PHB_EXPR pExpr;
+
+   pExpr = pSelf->value.asOperator.pLeft;
+
+   if( pExpr->ExprType == HB_ET_LOGICAL )
+   {
+      pExpr->value.asLogical = ! pExpr->value.asLogical;
+      HB_COMP_EXPR_CLEAR( pSelf );  /* suppress deletion of operator components */
+      pSelf = pExpr;
+   }
+   else if( pExpr->ExprType == HB_EO_NOT && HB_SUPPORT_EXTOPT )
+   {
+      /* NOTE: This will not generate a runtime error if incompatible
+       * data type is used
+       */
+      pExpr->ExprType = HB_ET_NONE; /* suppress deletion of operator components */
+      pExpr = pExpr->value.asOperator.pLeft;
+      HB_COMP_EXPR_FREE( pSelf );
+      pSelf = pExpr;
+   }
+   /* TODO: add checking of incompatible types
+      else
+      {
+      }
+    */
+
    return pSelf;
 }
 
diff --git a/src/harbour.def b/src/harbour.def
index a6ba1cc345..7f77d8e83a 100644
--- a/src/harbour.def
+++ b/src/harbour.def
@@ -2327,6 +2327,7 @@ hb_compExprReduceMod
 hb_compExprReduceMult
 hb_compExprReduceNE
 hb_compExprReduceNegate
+hb_compExprReduceNot
 hb_compExprReduceOr
 hb_compExprReducePlus
 hb_compExprReducePower