diff --git a/backend/plustek-pp_dac.c b/backend/plustek-pp_dac.c
index 522894aab..f0cfe4066 100644
--- a/backend/plustek-pp_dac.c
+++ b/backend/plustek-pp_dac.c
@@ -2221,7 +2221,7 @@ static void dacP98003AdjustShadingWaveform( pScanData ps )
        	    } else
                	pwsum->Red = 0;
 
-           	if((short)(pwsum->Green -= ps->Shade.DarkOffset.Colors.Green) > 0) {
+       	    if((short)(pwsum->Green -= ps->Shade.DarkOffset.Colors.Green) > 0) {
                	pwsum->Green = pwsum->Green * pRGB->Green / 100U;
            	    if( pwsum->Green > 0xfff )
                	    pwsum->Green = 0xfff;
diff --git a/backend/plustek-pp_image.c b/backend/plustek-pp_image.c
index ead9a6438..c7d2db258 100644
--- a/backend/plustek-pp_image.c
+++ b/backend/plustek-pp_image.c
@@ -1216,7 +1216,7 @@ static Bool imageP98003DataIsReady( pScanData ps )
 	        IORegisterToScanner( ps, ps->RegRefreshScanState );
 
 		/* direct is done here without copying...*/
-		if( fnDataDirect != ps->Scan.DataProcess ) {
+    	if( fnDataDirect != ps->Scan.DataProcess ) {
 			(*ps->Scan.DataProcess)(ps, (pVoid)(ps->Scan.bp.pMonoBuf ),
                                         (pVoid)(ps->Scan.BufPut.red.bp),
                                         ps->DataInf.dwAppPhyBytesPerLine);
diff --git a/backend/plustek-pp_motor.c b/backend/plustek-pp_motor.c
index 5c44b6d58..7f4b1acd0 100644
--- a/backend/plustek-pp_motor.c
+++ b/backend/plustek-pp_motor.c
@@ -1248,7 +1248,7 @@ static void motorP96WaitForPositionY( pScanData ps )
 	MiscStartTimer( &timer, _SECOND / 4);
     while (!MiscCheckTimer( &timer ));
 
-	memset( ps->a_nbNewAdrPointer, 0, _SCANSTATE_BYTES );
+    memset( ps->a_nbNewAdrPointer, 0, _SCANSTATE_BYTES );
 
     ps->Asic96Reg.RD_MotorControl = ps->IgnorePF|ps->MotorOn|_MotorDirForward;
     ps->Scan.fMotorBackward = _FALSE;
@@ -2671,7 +2671,7 @@ static void motorP98003WaitForPositionY( pScanData ps )
 
 	    while(( IOGetExtendedStatus( ps ) & _STILL_FREE_RUNNING) &&
                                                       !MiscCheckTimer(&timer));
-        	IODataToRegister( ps, ps->RegModeControl, _ModeScan );
+	    IODataToRegister( ps, ps->RegModeControl, _ModeScan );
     } else {
     	MotorP98003PositionYProc( ps, dwBeginY );
         IORegisterToScanner( ps, ps->RegRefreshScanState );
diff --git a/backend/plustek-pp_p12ccd.c b/backend/plustek-pp_p12ccd.c
index 178cb2e5e..1b64b4648 100644
--- a/backend/plustek-pp_p12ccd.c
+++ b/backend/plustek-pp_p12ccd.c
@@ -1105,7 +1105,7 @@ _LOC void P12InitCCDandDAC( pScanData ps, Bool shading )
 	    else
     		ps->Shade.bUniGain = 7;
 
-   		ps->Shade.wDarkLevels = 10;
+	    ps->Shade.wDarkLevels = 10;
 
 	    if( ps->Shade.bIntermediate & _ScanMode_Mono ) {
     		SamsungDAC8531[0].bParam = 0x57;
diff --git a/backend/plustek-pp_ptdrv.c b/backend/plustek-pp_ptdrv.c
index d88fba5ef..cb0eeb35f 100644
--- a/backend/plustek-pp_ptdrv.c
+++ b/backend/plustek-pp_ptdrv.c
@@ -1399,7 +1399,7 @@ static int ptdrvRead( pScanData ps, pUChar buffer, int count )
     else
         ps->Scan.fRefreshState = _TRUE;
 
-	ptdrvLampWarmup( ps );
+    ptdrvLampWarmup( ps );
 
 	if( _FALSE == ps->fScanningStatus ) {
 		retval = _E_ABORT;
@@ -1466,16 +1466,16 @@ static int ptdrvRead( pScanData ps, pUChar buffer, int count )
       		if( ps->Scan.dwLinesToRead > ps->DataInf.dwAppLinesPerArea )
         		ps->Scan.dwLinesToRead = ps->DataInf.dwAppLinesPerArea;
 
-			ps->DataInf.dwAppLinesPerArea -= ps->Scan.dwLinesToRead;
+      		ps->DataInf.dwAppLinesPerArea -= ps->Scan.dwLinesToRead;
 
       		if (ps->DataInf.dwScanFlag & SCANDEF_BmpStyle)
         		buffer += ((ps->Scan.dwLinesToRead - 1) *
                    				ps->DataInf.dwAppBytesPerLine);
 
-			if (ps->DataInf.dwVxdFlag & _VF_DATATOUSERBUFFER)
+      		if (ps->DataInf.dwVxdFlag & _VF_DATATOUSERBUFFER)
         		ps->DataInf.pCurrentBuffer = ps->Scan.bp.pMonoBuf;
 
-			while(ps->fScanningStatus && ps->Scan.dwLinesToRead) {
+      		while(ps->fScanningStatus && ps->Scan.dwLinesToRead) {
 
         		_ASSERT(ps->ReadOneImageLine);
 		   		if (!ps->ReadOneImageLine(ps)) {
@@ -1549,8 +1549,8 @@ static int ptdrvRead( pScanData ps, pUChar buffer, int count )
 ReadFinished:
 
 
-    if( _ASIC_IS_98003 == ps->sCaps.AsicID )
-        ps->CloseScanPath( ps );
+	if( _ASIC_IS_98003 == ps->sCaps.AsicID )
+		ps->CloseScanPath( ps );
 
 	if( NULL != ps->Scan.bp.pMonoBuf )
 		_KFREE( ps->Scan.bp.pMonoBuf );
diff --git a/backend/plustek_pp.c b/backend/plustek_pp.c
index c5b522838..adad34753 100644
--- a/backend/plustek_pp.c
+++ b/backend/plustek_pp.c
@@ -1537,7 +1537,7 @@ SANE_Status sane_control_option( SANE_Handle handle, SANE_Int option,
 	    			if( NULL != info )
     					*info |= SANE_INFO_RELOAD_PARAMS | SANE_INFO_RELOAD_OPTIONS;
 
-					mp       = getModeList( s );
+	    			mp       = getModeList( s );
 					scanmode = mp[s->val[OPT_MODE].w].scanmode;
 
 				    s->opt[OPT_GAMMA_VECTOR].cap   |= SANE_CAP_INACTIVE;
@@ -1702,7 +1702,7 @@ SANE_Status sane_control_option( SANE_Handle handle, SANE_Int option,
 					checkGammaSettings(s);
 	    			if( NULL != info )
 		    			*info |= SANE_INFO_RELOAD_PARAMS;
-					break;
+		    		break;
 
 			    default:
 				    return SANE_STATUS_INVAL;