diff --git a/DRAMSys/simulator/src/simulation/StlDataPlayer.h b/DRAMSys/simulator/src/simulation/StlDataPlayer.h
index 16905881..fbe6a67a 100644
--- a/DRAMSys/simulator/src/simulation/StlDataPlayer.h
+++ b/DRAMSys/simulator/src/simulation/StlDataPlayer.h
@@ -89,7 +89,7 @@ public:
         payload->set_data_ptr(dataElement);
 
         // set data:
-        for(int i = 0; i < bytesPerColumn*burstlength ; i++)
+        for(unsigned i = 0; i < bytesPerColumn*burstlength ; i++)
         {
             dataElement[i] = (unsigned char)std::stoi(data.substr(i*2,2).c_str(),0,16);
         }
diff --git a/DRAMSys/simulator/src/simulation/TracePlayer.h b/DRAMSys/simulator/src/simulation/TracePlayer.h
index a376a93a..1c2b250b 100644
--- a/DRAMSys/simulator/src/simulation/TracePlayer.h
+++ b/DRAMSys/simulator/src/simulation/TracePlayer.h
@@ -113,7 +113,7 @@ void TracePlayer<BUSWIDTH>::setDataPointer(gp* payload, unsigned char * dataElem
     //check if payload takes ownership
     payload->set_data_length(size);
     payload->set_data_ptr(dataElement);
-    for(int i = 0; i < size; i++)
+    for(unsigned i = 0; i < size; i++)
         dataElement[i] = 0;
 }