diff --git a/NmapOps.h b/NmapOps.h
index 4b4e5f45a..d322ed312 100644
--- a/NmapOps.h
+++ b/NmapOps.h
@@ -118,7 +118,7 @@ class NmapOps {
 // The time this obj. was instantiated   or last ReInit()ed.
   const struct timeval *getStartTime() { return &start_time; }
   // Number of milliseconds since getStartTime().  The current time is an
-  // optional argument to avoid an extre gettimeofday() call.
+  // optional argument to avoid an extra gettimeofday() call.
   int TimeSinceStartMS(struct timeval *now=NULL); 
   struct in_addr v4source();
   const struct in_addr *v4sourceip();
diff --git a/protocols.cc b/protocols.cc
index 28d5f82eb..abcefb6c1 100644
--- a/protocols.cc
+++ b/protocols.cc
@@ -121,7 +121,7 @@ static int nmap_protocols_init() {
   int res;
 
   if (nmap_fetchfile(filename, sizeof(filename), "nmap-protocols") != 1) {
-    error("Unable to find nmap-protocols!  Resorting to /etc/protocol");
+    error("Unable to find nmap-protocols!  Resorting to /etc/protocols");
     strcpy(filename, "/etc/protocols");
   }
 
diff --git a/tcpip.cc b/tcpip.cc
index 7e2da12a6..f0b430deb 100644
--- a/tcpip.cc
+++ b/tcpip.cc
@@ -159,7 +159,7 @@ setsockopt(sd, IPPROTO_IP, IP_HDRINCL, (const char *) &one, sizeof(one));
 }
 
 // Takes a protocol number like IPPROTO_TCP, IPPROTO_UDP, or
-// IPPROTO_TCP and returns a ascii representation (or "unknown" if it
+// IPPROTO_IP and returns a ascii representation (or "unknown" if it
 // doesn't recognize the number).  If uppercase is true, the returned
 // value will be in all uppercase letters.  You can skip this
 // parameter to use lowercase.
diff --git a/tcpip.h b/tcpip.h
index 5cd53d6a2..232f44cde 100644
--- a/tcpip.h
+++ b/tcpip.h
@@ -725,7 +725,7 @@ int isipprivate(const struct in_addr * const addr);
 int unblock_socket(int sd);
 
 // Takes a protocol number like IPPROTO_TCP, IPPROTO_UDP, or
-// IPPROTO_TCP and returns a ascii representation (or "unknown" if it
+// IPPROTO_IP and returns a ascii representation (or "unknown" if it
 // doesn't recognize the number).  If uppercase is true, the returned
 // value will be in all uppercase letters.  You can skip this
 // parameter to use lowercase.