diff --git a/putty.h b/putty.h
index e98bd7da..e2a7fea7 100644
--- a/putty.h
+++ b/putty.h
@@ -276,8 +276,8 @@ typedef struct {
     char termtype[32];
     char termspeed[32];
     char environmt[1024];	       /* VAR\tvalue\0VAR\tvalue\0\0 */
-    char username[32];
-    char localusername[32];
+    char username[100];
+    char localusername[100];
     int rfc_environ;
     int passive_telnet;
     /* Keyboard options */
diff --git a/ssh.c b/ssh.c
index 58b6b427..b2859651 100644
--- a/ssh.c
+++ b/ssh.c
@@ -2362,8 +2362,8 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
 		c_write_str("\r\n");
 	    }
 	} else {
-	    strncpy(username, cfg.username, 99);
-	    username[99] = '\0';
+	    strncpy(username, cfg.username, sizeof(username));
+	    username[sizeof(username)-1] = '\0';
 	}
 
 	send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
@@ -4182,8 +4182,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
 	    username[strcspn(username, "\n\r")] = '\0';
 	} else {
 	    char stuff[200];
-	    strncpy(username, cfg.username, 99);
-	    username[99] = '\0';
+	    strncpy(username, cfg.username, sizeof(username));
+	    username[sizeof(username)-1] = '\0';
 	    if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
 		sprintf(stuff, "Using username \"%s\".\r\n", username);
 		c_write_str(stuff);