diff --git a/src/lib/dhcp/pkt4.cc b/src/lib/dhcp/pkt4.cc
index c4d60ebe6d..d88894463f 100644
--- a/src/lib/dhcp/pkt4.cc
+++ b/src/lib/dhcp/pkt4.cc
@@ -81,6 +81,9 @@ Pkt4::Pkt4(const uint8_t* data, size_t len)
 
     data_.resize(len);
     memcpy(&data_[0], data, len);
+
+    memset(sname_, 0, MAX_SNAME_LEN);
+    memset(file_, 0, MAX_FILE_LEN);
 }
 
 size_t