diff --git a/DiskIOMeter.c b/DiskIOMeter.c
index 1c0c2ba4..1be40aa6 100644
--- a/DiskIOMeter.c
+++ b/DiskIOMeter.c
@@ -26,24 +26,24 @@ static const int DiskIOMeter_attributes[] = {
 };
 
 static bool hasData = false;
-static unsigned long int cached_read_diff;
-static unsigned long int cached_write_diff;
+static uint32_t cached_read_diff;
+static uint32_t cached_write_diff;
 static double cached_utilisation_diff;
 
 static void DiskIOMeter_updateValues(Meter* this, char* buffer, size_t len) {
-   static unsigned long long int cached_last_update;
+   static uint64_t cached_last_update;
 
    struct timeval tv;
    gettimeofday(&tv, NULL);
-   unsigned long long int timeInMilliSeconds = (unsigned long long int)tv.tv_sec * 1000 + (unsigned long long int)tv.tv_usec / 1000;
-   unsigned long long int passedTimeInMs = timeInMilliSeconds - cached_last_update;
+   uint64_t timeInMilliSeconds = (uint64_t)tv.tv_sec * 1000 + (uint64_t)tv.tv_usec / 1000;
+   uint64_t passedTimeInMs = timeInMilliSeconds - cached_last_update;
 
    /* update only every 500ms */
    if (passedTimeInMs > 500) {
-      static unsigned long long int cached_read_total;
-      static unsigned long long int cached_write_total;
-      static unsigned long long int cached_msTimeSpend_total;
-      unsigned long long int diff;
+      static uint64_t cached_read_total;
+      static uint64_t cached_write_total;
+      static uint64_t cached_msTimeSpend_total;
+      uint64_t diff;
 
       cached_last_update = timeInMilliSeconds;
 
@@ -59,18 +59,18 @@ static void DiskIOMeter_updateValues(Meter* this, char* buffer, size_t len) {
       if (data.totalBytesRead > cached_read_total) {
          diff = data.totalBytesRead - cached_read_total;
          diff /= 1024; /* Meter_humanUnit() expects unit in kilo */
-         cached_read_diff = (unsigned int)diff;
+         cached_read_diff = (uint32_t)diff;
       } else {
-         cached_read_diff = 0UL;
+         cached_read_diff = 0;
       }
       cached_read_total = data.totalBytesRead;
 
       if (data.totalBytesWritten > cached_write_total) {
          diff = data.totalBytesWritten - cached_write_total;
          diff /= 1024; /* Meter_humanUnit() expects unit in kilo */
-         cached_write_diff = (unsigned int)diff;
+         cached_write_diff = (uint32_t)diff;
       } else {
-         cached_write_diff = 0UL;
+         cached_write_diff = 0;
       }
       cached_write_total = data.totalBytesWritten;
 
diff --git a/DiskIOMeter.h b/DiskIOMeter.h
index 8b31dfa3..47afa5ed 100644
--- a/DiskIOMeter.h
+++ b/DiskIOMeter.h
@@ -10,9 +10,9 @@ in the source distribution for its full text.
 #include "Meter.h"
 
 typedef struct DiskIOData_ {
-   unsigned long long int totalBytesRead;
-   unsigned long long int totalBytesWritten;
-   unsigned long long int totalMsTimeSpend;
+   uint64_t totalBytesRead;
+   uint64_t totalBytesWritten;
+   uint64_t totalMsTimeSpend;
 } DiskIOData;
 
 extern const MeterClass DiskIOMeter_class;