diff --git a/libnetutil/netutil.cc b/libnetutil/netutil.cc
index 4d6212bd5..15bafdb58 100644
--- a/libnetutil/netutil.cc
+++ b/libnetutil/netutil.cc
@@ -1401,7 +1401,7 @@ struct tcpopt_info_ctx {
   bool valid;
   tcpopt_info_ctx() : p(NULL), end(NULL), valid(true) {}
   bool check_length(size_t len) const {
-    return (end - p) >= len;
+    return end >= (p + len);
   }
   void put_str(const char *str) {
     if (p >= end)
diff --git a/nping/EchoHeader.cc b/nping/EchoHeader.cc
index 1e58bc2aa..57765e3dd 100644
--- a/nping/EchoHeader.cc
+++ b/nping/EchoHeader.cc
@@ -849,8 +849,7 @@ int EchoHeader::setErrorMessage(const char *err){
   if(err==NULL){
     return OP_FAILURE;
   }else{
-    strncpy((char *)this->data_error->errmsg, err, ERROR_MSG_LEN);
-    this->data_error->errmsg[ERROR_MSG_LEN-1]='\0';
+    Strncpy((char *)this->data_error->errmsg, err, ERROR_MSG_LEN);
   }
   return OP_SUCCESS;
 } /* End of setErrorMessage() */
diff --git a/nse_zlib.cc b/nse_zlib.cc
index 26c996a3d..7a22e818e 100644
--- a/nse_zlib.cc
+++ b/nse_zlib.cc
@@ -844,7 +844,7 @@ static int lzlib_decompress(lua_State *L)
     zs.avail_in = avail_in;
 
     while(decompLimit > 0) {
-        unsigned int bufsize = LUAL_BUFFERSIZE;
+        int bufsize = LUAL_BUFFERSIZE;
         if (bufsize > decompLimit)
             bufsize = decompLimit;
         zs.next_out = (unsigned char*)luaL_prepbuffsize(&b, bufsize);
diff --git a/output.cc b/output.cc
index 24ab4acc2..995949f92 100644
--- a/output.cc
+++ b/output.cc
@@ -1996,7 +1996,7 @@ void printosscanoutput(const Target *currenths) {
 
   if (currenths->seq.responses > 3) {
     p = numlst;
-    size_t remaining = sizeof(numlst);
+    int remaining = sizeof(numlst);
     for (i = 0; i < currenths->seq.responses; i++) {
       int n = Snprintf(p, remaining, "%s%X",
           (p != numlst) ? "," : "", currenths->seq.seqs[i]);
@@ -2020,7 +2020,7 @@ void printosscanoutput(const Target *currenths) {
 
   if (currenths->seq.responses > 2) {
     p = numlst;
-    size_t remaining = sizeof(numlst);
+    int remaining = sizeof(numlst);
     for (i = 0; i < currenths->seq.responses; i++) {
       int n = Snprintf(p, remaining, "%s%hX",
           (p != numlst) ? "," : "", currenths->seq.ipids[i]);
diff --git a/tcpip.cc b/tcpip.cc
index c38ed41c6..1110403d3 100644
--- a/tcpip.cc
+++ b/tcpip.cc
@@ -1121,7 +1121,7 @@ int readtcppacket(const u8 *packet, int readdata) {
   bullshit2.s_addr = ip->ip_dst.s_addr;
   realfrag = htons(ntohs(ip->ip_off) & IP_OFFMASK);
   tot_len = htons(ip->ip_len);
-  strncpy(sourcehost, inet_ntoa(bullshit), 16);
+  Strncpy(sourcehost, inet_ntoa(bullshit), sizeof(sourcehost));
   if (ip->ip_hl >= 5 && tcp->th_off >= 5) {
     i = 4 * (ip->ip_hl + tcp->th_off);
   }