diff --git a/modules/mol/alg/src/domain_find.cc b/modules/mol/alg/src/domain_find.cc
index ffdfe53551eb8d8da500d2a07330eccae0f99e9b..0d5d9ba6147f42521a8e38b4f33a6a16f336d4d5 100644
--- a/modules/mol/alg/src/domain_find.cc
+++ b/modules/mol/alg/src/domain_find.cc
@@ -158,7 +158,7 @@ AdjacencyBitmap optimize_domains(AdjacencyBitmap adj1, Real tolerance,
         adj_rows_per_thread = adj_rows_per_thread+64-modulo;
       }
       for (int i=0;i<num_threads;++i) {
-        if (i*adj_rows_per_thread>adj1p->size()) {
+        if (size_t(i*adj_rows_per_thread) > adj1p->size()) {
           continue;
         }
         if (update_img) {
diff --git a/modules/mol/base/src/spatial_organizer.hh b/modules/mol/base/src/spatial_organizer.hh
index 8876473aa60ed477511029d00617401ff085a418..0e9dce74005141d9103453a806a475704d0ba2b2 100644
--- a/modules/mol/base/src/spatial_organizer.hh
+++ b/modules/mol/base/src/spatial_organizer.hh
@@ -117,7 +117,8 @@ public:
     Real dist2=dist*dist;
     Index imin = Index::Max(min_, gen_index(pos-VEC(dist,dist,dist)));
     Index imax = Index::Min(max_, gen_index(pos+VEC(dist,dist,dist)));
-    if ((imax.u-imin.u+1)*(imax.v-imin.v+1)*(imax.w-imin.w+1)>map_.size()) {
+    const size_t tmp = (imax.u-imin.u+1)*(imax.v-imin.v+1)*(imax.w-imin.w+1);
+    if (tmp > map_.size()) {
       return this->has_within_all_buckets(pos, dist2);
     }
     for(int wc=imin.w;wc<=imax.w;++wc) {
diff --git a/modules/seq/alg/src/contact_weight_matrix.cc b/modules/seq/alg/src/contact_weight_matrix.cc
index c90d67288f55642a593839e513d580308902b3fc..a8a18a5ebbf9d1319eda8995511f4e7f2af59dda 100644
--- a/modules/seq/alg/src/contact_weight_matrix.cc
+++ b/modules/seq/alg/src/contact_weight_matrix.cc
@@ -23,7 +23,8 @@
 namespace {
 std::map<char,int> init_dict(std::vector <char> aal){
   std::map<char,int> aa_dict;
-  for (int i=0;i!=aal.size();++i){
+  const int aal_size = static_cast<int>(aal.size());
+  for (int i=0;i!=aal_size;++i){
     aa_dict[aal[i]]=i;
   }
   return aa_dict;
diff --git a/modules/seq/alg/src/pair_subst_weight_matrix.cc b/modules/seq/alg/src/pair_subst_weight_matrix.cc
index b9b0a9c0112ba86000ee8d3fda8fa0337bfe0b1a..4d0216428ba09c9cf1b288957dc0626df335ebe3 100644
--- a/modules/seq/alg/src/pair_subst_weight_matrix.cc
+++ b/modules/seq/alg/src/pair_subst_weight_matrix.cc
@@ -25,7 +25,8 @@ namespace {
 
 std::map<char,int> init_dict(std::vector <char> aal){
   std::map<char,int> aa_dict;
-  for (int i=0;i!=aal.size();++i){
+  const int aal_size = static_cast<int>(aal.size());
+  for (int i=0;i!=aal_size;++i){
     aa_dict[aal[i]]=i;
   }
   return aa_dict;