diff --git a/DRAMSys/simulator/src/controller/core/configuration/Configuration.cpp b/DRAMSys/simulator/src/controller/core/configuration/Configuration.cpp
index c0f3cfb9..ada5409b 100644
--- a/DRAMSys/simulator/src/controller/core/configuration/Configuration.cpp
+++ b/DRAMSys/simulator/src/controller/core/configuration/Configuration.cpp
@@ -229,19 +229,19 @@ void Configuration::setParameters(std::map<std::string, std::string> parameterMa
 }
 
 // Returns the total memory size in bytes
-unsigned int Configuration::getSimMemSizeInBytes()
+std::uint64_t Configuration::getSimMemSizeInBytes()
 {
     // 1. Get number of banks, rows, columns and data width in bits for one die (or chip)
-    unsigned int banks = memSpec.NumberOfBanks;
-    unsigned int rows = memSpec.NumberOfRows;
-    unsigned int columns = memSpec.NumberOfColumns;
-    unsigned int bitWidth = memSpec.bitWidth;
+    std::uint64_t banks = memSpec.NumberOfBanks;
+    std::uint64_t rows = memSpec.NumberOfRows;
+    std::uint64_t columns = memSpec.NumberOfColumns;
+    std::uint64_t bitWidth = memSpec.bitWidth;
     // 2. Calculate size of one DRAM chip in bits
-    unsigned int chipBitSize = banks * rows * columns * bitWidth;
+    std::uint64_t chipBitSize = banks * rows * columns * bitWidth;
     // 3. Calculate size of one DRAM chip in bytes
-    unsigned int chipSize = chipBitSize / 8;
+    std::uint64_t chipSize = chipBitSize / 8;
     // 4. Total memory size in Bytes of one DIMM (with only support of 1 rank on a DIMM)
-    unsigned int memorySize = chipSize * NumberOfDevicesOnDIMM;
+    std::uint64_t memorySize = chipSize * NumberOfDevicesOnDIMM;
     assert(memorySize > 0);
     return memorySize;
 }
diff --git a/DRAMSys/simulator/src/controller/core/configuration/Configuration.h b/DRAMSys/simulator/src/controller/core/configuration/Configuration.h
index f2a7a463..53437269 100644
--- a/DRAMSys/simulator/src/controller/core/configuration/Configuration.h
+++ b/DRAMSys/simulator/src/controller/core/configuration/Configuration.h
@@ -100,7 +100,7 @@ struct Configuration
     // Temperature Simulation related
     TemperatureSimConfig temperatureSim;
 
-    unsigned int getSimMemSizeInBytes();
+    std::uint64_t getSimMemSizeInBytes();
     unsigned int getDataBusWidth();
     unsigned int getBytesPerBurst();
 
diff --git a/DRAMSys/simulator/src/simulation/Dram.h b/DRAMSys/simulator/src/simulation/Dram.h
index d7fa9e01..b9f74722 100644
--- a/DRAMSys/simulator/src/simulation/Dram.h
+++ b/DRAMSys/simulator/src/simulation/Dram.h
@@ -92,7 +92,7 @@ struct Dram : sc_module
 
     SC_CTOR(Dram) : tSocket("socket")
     {
-        unsigned int memorySize = Configuration::getInstance().getSimMemSizeInBytes();
+        std::uint64_t memorySize = Configuration::getInstance().getSimMemSizeInBytes();
         // allocate and model storage of one DRAM channel using memory map
         memory = (unsigned char *)mmap(NULL, memorySize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, -1, 0);