diff --git a/toonz/sources/image/avi/tiio_avi.cpp b/toonz/sources/image/avi/tiio_avi.cpp
index 0f7825f..121079f 100644
--- a/toonz/sources/image/avi/tiio_avi.cpp
+++ b/toonz/sources/image/avi/tiio_avi.cpp
@@ -544,9 +544,6 @@ void TLevelWriterAvi::doSaveSoundTrack() {
   WAVEFORMATEX waveinfo;
   int ret;
   LONG lSampWritten, lBytesWritten;
-  int rc;
-
-  rc = FALSE;
 
   AVISTREAMINFO audioStreamInfo;
   memset(&audioStreamInfo, 0, sizeof(AVISTREAMINFO));
diff --git a/toonz/sources/tnztools/autofilltlv.cpp b/toonz/sources/tnztools/autofilltlv.cpp
index 509e173..a854c89 100644
--- a/toonz/sources/tnztools/autofilltlv.cpp
+++ b/toonz/sources/tnztools/autofilltlv.cpp
@@ -264,7 +264,7 @@ bool rect_autofill_apply(const TToonzImageP &imgToApply, int x1, int y1, int x2,
   /*..........................................................................*/
   /* Matching basato sulla probabilita' di colore                             */
   /*..........................................................................*/
-  if (FALSE) {
+  if (false) {
     bool recomputeBBox = false;
     for (i = 0; i < F_work.n; i++) {
       if (F_work.array[i].match < 0) {
@@ -453,7 +453,7 @@ bool autofill_apply(const TToonzImageP &imgToApply, bool selective,
     /*..........................................................................*/
     /* Matching basato sulla probabilita' di colore */
     /*..........................................................................*/
-    if (FALSE) {
+    if (false) {
       bool recomputeBBox = false;
       for (i = 0; i < F_work.n; i++) {
         if (F_work.array[i].match < 0) {
@@ -759,7 +759,7 @@ static void rinomina(int regione1, int regione2, int num_regioni,
 {
   struct vicine *appo, *old, appo1;
   int i;
-  int trovato = FALSE;
+  bool trovato = false;
 
   PRINTF("Rinomino %d %d Regioni: %d \n", regione1, regione2, num_regioni);
   /* mostra_vicini(rlst);  */
@@ -791,7 +791,7 @@ static void rinomina(int regione1, int regione2, int num_regioni,
             appo->region_id = regione2;
             old             = appo;
             appo            = appo->next;
-            trovato         = TRUE;
+            trovato         = true;
           }
         } else /* region_id non e' region2 o regione 1 */
         {
diff --git a/toonz/sources/toonzlib/trastercentroid.cpp b/toonz/sources/toonzlib/trastercentroid.cpp
index 4f538ab..b667d6c 100644
--- a/toonz/sources/toonzlib/trastercentroid.cpp
+++ b/toonz/sources/toonzlib/trastercentroid.cpp
@@ -15,11 +15,6 @@
 #include "tmsg.h"
 #include "copP.h"*/
 
-#if defined(MACOSX) || defined(LINUX)
-#define TRUE 1
-#define FALSE 0
-#endif
-
 /*------------------------------------------------------------------------*/
 namespace {
 UCHAR First_preseed_table[256] = {
@@ -187,7 +182,7 @@ int Displace_vector[8];
     y_pos++;                                                                   \
     break;                                                                     \
   default:                                                                     \
-    assert(FALSE);                                                             \
+    assert(false);                                                             \
   }
 
 /*------------------------------------------------------------------------*/
@@ -232,7 +227,7 @@ static void initialize_displace_vector(void) {
 
 /*------------------------------------------------------------------------*/
 
-static int find_next_seed(const TRasterGR8P &r, int first_seed, UCHAR *&seed,
+static int find_next_seed(const TRasterGR8P &r, bool first_seed, UCHAR *&seed,
                           int &x_pos, int &y_pos) {
   static int Curr_x = 0, Curr_y = 0;
   UCHAR *pix;
@@ -277,7 +272,7 @@ static void doComputeCentroid(const TRasterGR8P &r, TPoint &cp) {
   int x_num = 0, y_num = 0, den = 0;
   int x_pos, y_pos, old_x_pos, old_y_pos;
   int aux, old_displ = -1;
-  int first_seed;
+  bool first_seed;
 
   Lx                 = r->getLx();
   Displace_vector[0] = -Lx - 1;
@@ -289,10 +284,10 @@ static void doComputeCentroid(const TRasterGR8P &r, TPoint &cp) {
   Displace_vector[6] = Lx;
   Displace_vector[7] = Lx + 1;
 
-  first_seed = TRUE;
+  first_seed = true;
 
   while (find_next_seed(r, first_seed, seed, x_pos, y_pos)) {
-    first_seed = FALSE;
+    first_seed = false;
 
     *seed |= 0x2;