diff --git a/.gitattributes b/.gitattributes
index 6f212c9186..8af203a076 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -18357,6 +18357,10 @@ tests/webtbs/tw3669.pp svneol=native#text/plain
 tests/webtbs/tw36698.pp -text svneol=native#text/pascal
 tests/webtbs/tw36738.pp svneol=native#text/pascal
 tests/webtbs/tw3676.pp svneol=native#text/plain
+tests/webtbs/tw36775.pp svneol=native#text/pascal
+tests/webtbs/tw36775a.pp svneol=native#text/pascal
+tests/webtbs/tw36775b.pp -text svneol=native#text/pascal
+tests/webtbs/tw36775c.pp -text svneol=native#text/pascal
 tests/webtbs/tw3681.pp svneol=native#text/plain
 tests/webtbs/tw3683.pp svneol=native#text/plain
 tests/webtbs/tw36863.pp svneol=native#text/pascal
diff --git a/compiler/nadd.pas b/compiler/nadd.pas
index b6acb47a21..1380d3e0ff 100644
--- a/compiler/nadd.pas
+++ b/compiler/nadd.pas
@@ -1443,7 +1443,7 @@ implementation
                           { full boolean evaluation is only useful if the nodes are not too complex and if no flags/jumps must be converted,
                             further, we need to know the expectloc }
                           if (node_complexity(right)<=2) and
-                            not(left.expectloc in [LOC_JUMP,LOC_INVALID]) and not(right.expectloc in [LOC_JUMP,LOC_INVALID]) then
+                            not(left.expectloc in [LOC_FLAGS,LOC_JUMP,LOC_INVALID]) and not(right.expectloc in [LOC_FLAGS,LOC_JUMP,LOC_INVALID]) then
                             begin
                               { we need to copy the whole tree to force another pass_1 }
                               include(localswitches,cs_full_boolean_eval);
diff --git a/tests/webtbs/tw36775.pp b/tests/webtbs/tw36775.pp
new file mode 100644
index 0000000000..3f0261dbe0
--- /dev/null
+++ b/tests/webtbs/tw36775.pp
@@ -0,0 +1,152 @@
+program tw36775;
+
+{$mode objfpc}
+
+{ NOTE: The important part of this test is on line 65, the FindByName method }
+
+uses
+  SysUtils;
+
+type
+  TTestItem = class;
+
+  TTestCollection = class
+    private
+      FItemArray: array of TTestItem;
+      function GetItem(const Index: Integer): TTestItem;
+      function GetCount: Integer;
+    public
+      destructor Destroy; override;
+      function Add(const Item: TTestItem): Integer;
+      function FindByName(const Val: ansistring; Ignore: TTestItem = nil): TTestItem;
+      property Items[Index: Integer]: TTestItem read GetItem;
+      property Count: Integer read GetCount;
+  end;
+
+  TTestItem = class
+    private
+      FName: ansistring;
+    public
+      constructor Create(Owner: TTestCollection; AName: ansistring);
+      property Name: ansistring read FName;
+  end;
+
+{ TTestCollection }
+
+destructor TTestCollection.Destroy;
+  var
+    i: Integer;
+  begin
+    for i := 0 to Count - 1 do
+      FItemArray[i].Free;
+
+    inherited Destroy;
+  end;
+
+function TTestCollection.GetItem(const Index: Integer): TTestItem;
+  begin
+    Result := FItemArray[Index];
+  end;
+
+function TTestCollection.GetCount: Integer;
+  begin
+    Result := Length(FItemArray);
+  end;
+
+function TTestCollection.Add(const Item: TTestItem): Integer;
+  begin
+    Result := Length(FItemArray);
+    SetLength(FItemArray, Result + 1);
+    FItemArray[Result] := Item;
+  end;
+
+{ NOTE - The construction of the internal loop in the method below, specifically
+    the setting of Result, is paramount for triggering Internal Error 200405231 }
+function TTestCollection.FindByName(const Val: ansistring; Ignore: TTestItem): TTestItem;
+  var
+    i: Integer;
+  begin
+    i := Count - 1;
+    while i >= 0 do
+    begin
+      Result := Items[i];
+      { If either one of the conditions is removed, the internal error does not trigger }
+      if (AnsiCompareText(Result.Name, Val) = 0) and (Ignore <> Result) then
+        Exit;
+      Dec(i);
+    end;
+    Result := nil;
+  end;
+
+{ TTestItem }
+
+constructor TTestItem.Create(Owner: TTestCollection; AName: ansistring);
+  begin
+    FName := AName;
+    Owner.Add(Self);
+  end;
+
+const
+  TestName1 = 'Low';
+  TestName2 = 'Defrost';
+  TestName3 = 'Medium';
+  TestName4 = 'Medium High';
+  TestName5 = 'Cook';
+  TestNameX = 'High';
+
+var
+  Collection: TTestCollection;
+  ReturnedItem, IgnoreMe: TTestItem;
+begin
+  Collection := TTestCollection.Create;
+  try
+    TTestItem.Create(Collection, TestName1);
+    TTestItem.Create(Collection, TestName2);
+    TTestItem.Create(Collection, TestName3);
+    TTestItem.Create(Collection, TestName4);
+    TTestItem.Create(Collection, TestName5);
+    IgnoreMe := TTestItem.Create(Collection, TestName3); { A second item named "Medium" }
+
+    ReturnedItem := Collection.FindByName(TestName2);
+    if not Assigned(ReturnedItem) then
+      begin
+        WriteLn('ERROR: Collection.FindByName(', TestName2, ') returned nil.');
+        Halt(1);
+      end
+    else if ReturnedItem.Name <> TestName2 then
+      begin
+        WriteLn('ERROR: Collection.FindByName(', TestName2, ') returned the wrong item (', ReturnedItem.Name, ').');
+        Halt(1);
+      end;
+
+    ReturnedItem := Collection.FindByName(TestNameX);
+    if Assigned(ReturnedItem) then
+      begin
+        WriteLn('ERROR: Collection.FindByName(', TestNameX, ') did not return nil (', ReturnedItem.Name, ').');
+        Halt(1);
+      end;
+
+    ReturnedItem := Collection.FindByName(TestName3, IgnoreMe);
+    if not Assigned(ReturnedItem) then
+      begin
+        WriteLn('ERROR: Collection.FindByName(', TestName3, ') returned nil.');
+        Halt(1);
+      end
+    else if ReturnedItem.Name <> TestName3 then
+      begin
+        WriteLn('ERROR: Collection.FindByName(', TestName3, ') returned the wrong item (', ReturnedItem.Name, ').');
+        Halt(1);
+      end
+    else if ReturnedItem = IgnoreMe then
+      begin
+        WriteLn('ERROR: Collection.FindByName(', TestName3, ') returned the ignored item.');
+        Halt(1);
+      end;
+
+  finally
+    Collection.Free;
+  end;
+
+  WriteLn('ok');
+end.
+
diff --git a/tests/webtbs/tw36775a.pp b/tests/webtbs/tw36775a.pp
new file mode 100644
index 0000000000..7ba921fba6
--- /dev/null
+++ b/tests/webtbs/tw36775a.pp
@@ -0,0 +1,2 @@
+{ %OPT=-O2 }
+{$i tw36775.pp}
diff --git a/tests/webtbs/tw36775b.pp b/tests/webtbs/tw36775b.pp
new file mode 100644
index 0000000000..7e76ab84a7
--- /dev/null
+++ b/tests/webtbs/tw36775b.pp
@@ -0,0 +1,2 @@
+{ %OPT=-O3 }
+{$i tw36775.pp}
\ No newline at end of file
diff --git a/tests/webtbs/tw36775c.pp b/tests/webtbs/tw36775c.pp
new file mode 100644
index 0000000000..4e442b4094
--- /dev/null
+++ b/tests/webtbs/tw36775c.pp
@@ -0,0 +1,2 @@
+{ %OPT=-O4 }
+{$i tw36775.pp}
\ No newline at end of file