diff --git a/src/EasyNTPClient.cpp b/src/EasyNTPClient.cpp
index 22a2620..c0991d7 100644
--- a/src/EasyNTPClient.cpp
+++ b/src/EasyNTPClient.cpp
@@ -41,9 +41,17 @@ void EasyNTPClient::setTimeOffset (int offset) {
 
 unsigned long EasyNTPClient::getServerTime () {
     static int udpInited = this->mUdp->begin(123); // open socket on arbitrary port
-    // Only the first four bytes of an outgoing NTP packet need to be set
-    // appropriately, the rest can be whatever.
-    const long ntpFirstFourBytes = 0xEC0600E3; // NTP request header
+    // Only the first four bytes of an NTP request have to be set. The rest
+    // of the packet has to be 0, to avoid the server getting confused with the
+    // timestamps.
+    // see https://labs.apnic.net/?p=462 for details about the NTP packet
+    // structure
+    byte packetBuffer[NTP_PACKET_SIZE] = {0};
+
+    packetBuffer[0] = NTP_HEADER_LI|NTP_HEADER_VN|NTP_HEADER_MODE;
+    // packetBuffer[1] (stratum) skipped because it is already 0
+    packetBuffer[2] = 6;    // polling interval in log2 seconds
+    packetBuffer[3] = 0xEC; // precision
 
     // Fail if WiFiUdp.begin() could not init a socket
     if (! udpInited)
@@ -54,7 +62,7 @@ unsigned long EasyNTPClient::getServerTime () {
 
     // Send an NTP request
     if (! (this->mUdp->beginPacket(this->mServerPool, 123) // 123 is the NTP port
-    && this->mUdp->write((byte *)&ntpFirstFourBytes, 48) == 48
+    && this->mUdp->write(packetBuffer, NTP_PACKET_SIZE) == NTP_PACKET_SIZE
     && this->mUdp->endPacket()))
     return 0;       // sending request failed
 
@@ -63,31 +71,28 @@ unsigned long EasyNTPClient::getServerTime () {
     const byte maxPoll = 15;    // poll up to this many times
     int pktLen;       // received packet length
     for (byte i=0; i<maxPoll; i++) {
-    if ((pktLen = this->mUdp->parsePacket()) == 48)
-      break;
-    delay(pollIntv);
+    	if ((pktLen = this->mUdp->parsePacket()) == NTP_PACKET_SIZE)
+      	break;
+    	delay(pollIntv);
     }
-    if (pktLen != 48)
-    return 0;       // no correct packet received
+    if (pktLen != NTP_PACKET_SIZE)
+	    return 0;       // no correct packet received
 
-    // Read and discard the first useless bytes
-    // Set useless to 32 for speed; set to 40 for accuracy.
-    const byte useless = 40;
-    for (byte i = 0; i < useless; ++i)
-    this->mUdp->read();
+    this->mUdp->read(packetBuffer, NTP_PACKET_SIZE);
 
-    // Read the integer part of sending time
-    unsigned long time = this->mUdp->read();  // NTP time
-    for (byte i = 1; i < 4; i++)
-    time = time << 8 | this->mUdp->read();
+    // Read the integer part (32 bits) of the Transmit Timestamp (64 bits total)
+    unsigned long time = packetBuffer[NTP_TX_TIMESTAMP_OFFSET];
+    time = time << 8 | packetBuffer[NTP_TX_TIMESTAMP_OFFSET + 1];
+    time = time << 8 | packetBuffer[NTP_TX_TIMESTAMP_OFFSET + 2];
+    time = time << 8 | packetBuffer[NTP_TX_TIMESTAMP_OFFSET + 3];
 
     // Round to the nearest second if we want accuracy
-    // The fractionary part is the next byte divided by 256: if it is
+    // The fractionary part is the last byte divided by 256: if it is
     // greater than 500ms we round to the next second; we also account
     // for an assumed network delay of 50ms, and (0.5-0.05)*256=115;
     // additionally, we account for how much we delayed reading the packet
     // since its arrival, which we assume on average to be pollIntv/2.
-    time += (this->mUdp->read() > 115 - pollIntv/8);
+    time += (packetBuffer[NTP_TX_TIMESTAMP_OFFSET + 4] > 115 - pollIntv/8);
 
     // Discard the rest of the packet
     this->mUdp->flush();
diff --git a/src/EasyNTPClient.h b/src/EasyNTPClient.h
index 003b32f..654da94 100644
--- a/src/EasyNTPClient.h
+++ b/src/EasyNTPClient.h
@@ -17,6 +17,16 @@
 #include "Arduino.h"
 #include <Udp.h>
 
+/*
+ * NTP packet-related macros.
+ * see https://labs.apnic.net/?p=462 for details about the NTP packet structure.
+ */
+#define NTP_PACKET_SIZE 48 // Size of an NTP packet
+#define NTP_HEADER_LI   0b11000000 // leap indicator = 3 (unsynchronized)
+#define NTP_HEADER_VN   0b00100000 // version number = 4
+#define NTP_HEADER_MODE 0b00000011 // mode = 3 (client)
+#define NTP_TX_TIMESTAMP_OFFSET 40 // offset within the packet for the TX time
+
 class EasyNTPClient
 {
   public:
@@ -37,4 +47,4 @@ class EasyNTPClient
     unsigned long getServerTime();
 };
 
-#endif
\ No newline at end of file
+#endif