diff --git a/compiler2/CodeGenHelper.cc b/compiler2/CodeGenHelper.cc
index 6e6371301dce18f5b2fab1099d21623b26914901..f903b70a880065e63eb9f7702811658915ad3dee 100644
--- a/compiler2/CodeGenHelper.cc
+++ b/compiler2/CodeGenHelper.cc
@@ -136,7 +136,7 @@ bool CodeGenHelper::set_split_mode(const char* type) {
     split_to_slices = false;
   } else if ((n = atoi(type))) {
     size_t length = strlen(type);
-    for (int i=0;i<length; i++) {
+    for (size_t i=0;i<length; i++) {
       if (!isdigit(type[i])) {
         ERROR("The number argument of -U must be a valid number.");
         break;
@@ -278,7 +278,7 @@ void CodeGenHelper::get_chunk_from_poslist(const char* from, char *& to, const s
   if (pos > base_pos) { // If we haven't finished with this interval_array
     if (pos - base_pos >= chunk_size) { // It is a good chunk, but make it more precise because it may be too big
       int ind = 0;
-      for (int i = 0; i <= interval_array_size; i++) {
+      for (size_t i = 0; i <= interval_array_size; i++) {
         if (tmp + interval_array[i] <= base_pos) { // Find the pos where we left off
           ind = i;
         } else if (tmp + interval_array[i] - base_pos >= chunk_size) {
@@ -290,7 +290,7 @@ void CodeGenHelper::get_chunk_from_poslist(const char* from, char *& to, const s
       }
     } else { // We can't form a new chunk from the remaining characters
       int ind = 0;
-      for (int i = 0; i <= interval_array_size; i++) {
+      for (size_t i = 0; i <= interval_array_size; i++) {
         if (tmp + interval_array[i] <= base_pos) {
           ind = i;
         } else {
diff --git a/compiler2/makefile.c b/compiler2/makefile.c
index 629c5ec70c87b90c33b10b34d0bc5427db066408..c0d53c5cbcca2b0b1474ecd42186247839573c2f 100644
--- a/compiler2/makefile.c
+++ b/compiler2/makefile.c
@@ -4376,7 +4376,7 @@ int main(int argc, char *argv[])
           "'none', 'type', or a number.", optarg);
       } else {
         size_t length = strlen(optarg);
-        for (int i=0;i<length; i++) {
+        for (size_t i=0;i<length; i++) {
           if (!isdigit(optarg[i])) {
             ERROR("The number argument of -U must be a valid number.");
             break;