diff --git a/components/fpspreadsheet/source/common/fpsexprparser.pas b/components/fpspreadsheet/source/common/fpsexprparser.pas
index eeb9e717d..d7ee6a056 100644
--- a/components/fpspreadsheet/source/common/fpsexprparser.pas
+++ b/components/fpspreadsheet/source/common/fpsexprparser.pas
@@ -4310,8 +4310,8 @@ begin
       exit;
     end;
     for formula in sheet.Formulas do
-      if (formula^.Row >= r[1]) and (formula^.Row <= r[2]) and
-         (formula^.Col >= c[1]) and (formula^.Col <= c[2])
+      if (Integer(formula^.Row) >= r[1]) and (Integer(formula^.Row) <= r[2]) and
+         (Integer(formula^.Col) >= c[1]) and (Integer(formula^.Col) <= c[2])
       then
         case formula^.CalcState of
           csNotCalculated:
diff --git a/components/fpspreadsheet/source/common/fpsfunc.pas b/components/fpspreadsheet/source/common/fpsfunc.pas
index 0095eb76f..136c181bf 100644
--- a/components/fpspreadsheet/source/common/fpsfunc.pas
+++ b/components/fpspreadsheet/source/common/fpsfunc.pas
@@ -2115,14 +2115,11 @@ var
   arg: TsExpressionResult;
   sheet: TsWorksheet;
   book: TsWorkbook;
-  f: TsRelFlags;
 
   function Matches(ACell: PCell): Boolean;
   var
     cellval: Double;
     s: String;
-
-    ok: boolean;
   begin
     Result := false;
     if ACell = nil then exit;
@@ -2148,7 +2145,6 @@ var
        -1 : Result := cellval >= numSearchValue;
       end;
     end;
-    ok := result;
   end;
 
 begin
diff --git a/components/fpspreadsheet/source/common/fpsreaderwriter.pas b/components/fpspreadsheet/source/common/fpsreaderwriter.pas
index a749595d1..e1c5f72c8 100644
--- a/components/fpspreadsheet/source/common/fpsreaderwriter.pas
+++ b/components/fpspreadsheet/source/common/fpsreaderwriter.pas
@@ -363,6 +363,7 @@ end;
 -------------------------------------------------------------------------------}
 class function TsCustomSpreadReader.CheckFileFormat(AStream: TStream): boolean;
 begin
+  Unused(AStream);
   Result := true;
 end;
 
@@ -371,6 +372,7 @@ end;
 -------------------------------------------------------------------------------}
 class function TsCustomSpreadReader.CheckFileFormatDetails(AStream: TStream): Boolean;
 begin
+  Unused(AStream);
   Result := true;
 end;
 
diff --git a/components/fpspreadsheet/source/common/fpsxmlcommon.pas b/components/fpspreadsheet/source/common/fpsxmlcommon.pas
index a771fff26..c970c8465 100644
--- a/components/fpspreadsheet/source/common/fpsxmlcommon.pas
+++ b/components/fpspreadsheet/source/common/fpsxmlcommon.pas
@@ -419,7 +419,7 @@ const
   ZIP_HEADER: packed array[0..1] of char = ('P', 'K');
 var
   P: Int64;
-  buf: packed array[0..1] of char;
+  buf: packed array[0..1] of char = (#0, #0);
 begin
   Result := false;
   P := AStream.Position;
diff --git a/components/fpspreadsheet/source/common/xlsbiff2.pas b/components/fpspreadsheet/source/common/xlsbiff2.pas
index a4d425fd1..ee9411b9a 100644
--- a/components/fpspreadsheet/source/common/xlsbiff2.pas
+++ b/components/fpspreadsheet/source/common/xlsbiff2.pas
@@ -342,7 +342,7 @@ const
     $09,$00, $04,$00);  // they are common to all BIFF2 files that I've seen
 var
   P: Int64;
-  buf: packed array[0..3] of byte;
+  buf: packed array[0..3] of byte = (0, 0, 0, 0);
   n: Integer;
 begin
   Result := false;
@@ -1044,7 +1044,7 @@ begin
     $02: AStream.ReadByte;   // tAttrIF, not explicitely used
     $04: begin               // tAttrChoose, not supported
            nc := AStream.ReadByte;
-           AStream.Position := AStream.Position + 2*nc + 1;
+           AStream.Position := AStream.Position + 2*Int64(nc) + 1;
          end;
     $08: AStream.ReadByte;   // tAttrSkip, data not used
     $10: AStream.ReadByte;   // tAttrSum, to be processed by ReadRPNTokenArray, byte not used
diff --git a/components/fpspreadsheet/source/common/xlscommon.pas b/components/fpspreadsheet/source/common/xlscommon.pas
index a1a0be352..43d11db32 100644
--- a/components/fpspreadsheet/source/common/xlscommon.pas
+++ b/components/fpspreadsheet/source/common/xlscommon.pas
@@ -1191,7 +1191,7 @@ const
     $D0,$CF, $11,$E0, $A1,$B1, $1A,$E1);
 var
   P: Int64;
-  buf: packed array[0..7] of byte;
+  buf: packed array[0..7] of byte = (0, 0, 0, 0, 0, 0, 0, 0);
   n: Integer;
 begin
   Result := false;
@@ -2582,7 +2582,7 @@ end;
 -------------------------------------------------------------------------------}
 procedure TsSpreadBIFFReader.ReadRPNAttr(AStream: TStream; AIdentifier: Byte);
 var
-  nc: Integer;
+  nc: Int64;
 begin
   case AIdentifier of
     $01: AStream.ReadWord;     // tAttrVolatile token, skip
@@ -3027,7 +3027,7 @@ var
   rpnItem: PRPNItem;
   supported: boolean;
   dblVal: Double = 0.0;   // IEEE 8 byte floating point number
-  flags, flags2: TsRelFlags;
+  flags: TsRelFlags;
   r, c, r2, c2: Cardinal;
   dr, dc, dr2, dc2: Integer;
   fek: TFEKind;
diff --git a/components/fpspreadsheet/source/common/xlsxooxml.pas b/components/fpspreadsheet/source/common/xlsxooxml.pas
index 8044df2d1..605d7f66f 100644
--- a/components/fpspreadsheet/source/common/xlsxooxml.pas
+++ b/components/fpspreadsheet/source/common/xlsxooxml.pas
@@ -4134,7 +4134,7 @@ var
   ext: String;
   img: TsImage;
   rId: Integer;
-  hlink, target, bookmark: String;
+  target, bookmark: String;
   u: TURI;
   sheet: TsWorksheet absolute AWorksheet;
 begin