diff --git a/src/algorithms/signal_source/libs/gnss_sdr_valve.cc b/src/algorithms/signal_source/libs/gnss_sdr_valve.cc
index d599684ff..aa2bd1237 100644
--- a/src/algorithms/signal_source/libs/gnss_sdr_valve.cc
+++ b/src/algorithms/signal_source/libs/gnss_sdr_valve.cc
@@ -99,15 +99,15 @@ int Gnss_Sdr_Valve::work(int noutput_items,
                 {
                     return 0;
                 }
-            //multichannel support
-            for (int ch = 0; ch < output_items.size(); ch++)
+            // multichannel support
+            for (unsigned int ch = 0; ch < output_items.size(); ch++)
                 {
                     memcpy(output_items[ch], input_items[ch], n * input_signature()->sizeof_stream_item(ch));
                 }
             d_ncopied_items += n;
             return n;
         }
-    for (int ch = 0; ch < output_items.size(); ch++)
+    for (unsigned int ch = 0; ch < output_items.size(); ch++)
         {
             memcpy(output_items[ch], input_items[ch], noutput_items * input_signature()->sizeof_stream_item(ch));
         }
diff --git a/src/core/receiver/gnss_flowgraph.cc b/src/core/receiver/gnss_flowgraph.cc
index 8af07e1e7..0611a4e26 100644
--- a/src/core/receiver/gnss_flowgraph.cc
+++ b/src/core/receiver/gnss_flowgraph.cc
@@ -218,7 +218,7 @@ void GNSSFlowgraph::connect()
 // Signal Source (i) >  Signal conditioner (i) >
 #ifndef ENABLE_FPGA
     int RF_Channels = 0;
-    int signal_conditioner_ID = 0;
+    unsigned int signal_conditioner_ID = 0;
     for (int i = 0; i < sources_count_; i++)
         {
             try