diff --git a/ser_posix.c b/ser_posix.c
index accabb02..210bff20 100644
--- a/ser_posix.c
+++ b/ser_posix.c
@@ -152,7 +152,7 @@ static int ser_setspeed(union filedescriptor *fd, long baud)
  * terminal/console server with serial parameters configured
  * appropriately (e. g. 115200-8-N-1 for a STK500.)
  */
-static void
+static int
 net_open(const char *port, union filedescriptor *fdp)
 {
   char *hstr, *pstr, *end;
@@ -164,14 +164,14 @@ net_open(const char *port, union filedescriptor *fdp)
   if ((hstr = strdup(port)) == NULL) {
     fprintf(stderr, "%s: net_open(): Out of memory!\n",
 	    progname);
-    exit(1);
+    return -1;
   }
 
   if (((pstr = strchr(hstr, ':')) == NULL) || (pstr == hstr)) {
     fprintf(stderr, "%s: net_open(): Mangled host:port string \"%s\"\n",
 	    progname, hstr);
     free(hstr);
-    exit(1);
+    return -1;
   }
 
   /*
@@ -185,14 +185,14 @@ net_open(const char *port, union filedescriptor *fdp)
     fprintf(stderr, "%s: net_open(): Bad port number \"%s\"\n",
 	    progname, pstr);
     free(hstr);
-    exit(1);
+    return -1;
   }
 
   if ((hp = gethostbyname(hstr)) == NULL) {
     fprintf(stderr, "%s: net_open(): unknown host \"%s\"\n",
 	    progname, hstr);
     free(hstr);
-    exit(1);
+    return -1;
   }
 
   free(hstr);
@@ -200,7 +200,7 @@ net_open(const char *port, union filedescriptor *fdp)
   if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
     fprintf(stderr, "%s: net_open(): Cannot open socket: %s\n",
 	    progname, strerror(errno));
-    exit(1);
+    return -1;
   }
 
   memset(&sockaddr, 0, sizeof(struct sockaddr_in));
@@ -211,10 +211,11 @@ net_open(const char *port, union filedescriptor *fdp)
   if (connect(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
     fprintf(stderr, "%s: net_open(): Connect failed: %s\n",
 	    progname, strerror(errno));
-    exit(1);
+    return -1;
   }
 
   fdp->ifd = fd;
+  return 0;
 }
 
 
@@ -257,8 +258,7 @@ static int ser_open(char * port, long baud, union filedescriptor *fdp)
    * handle it as a TCP connection to a terminal server.
    */
   if (strncmp(port, "net:", strlen("net:")) == 0) {
-    net_open(port + strlen("net:"), fdp);
-    return 0;
+    return net_open(port + strlen("net:"), fdp);
   }
 
   /*
diff --git a/ser_win32.c b/ser_win32.c
index 9d8bf7aa..4b55646b 100644
--- a/ser_win32.c
+++ b/ser_win32.c
@@ -112,7 +112,7 @@ static int ser_setspeed(union filedescriptor *fd, long baud)
 }
 
 
-static void ser_open(char * port, long baud, union filedescriptor *fdp)
+static int ser_open(char * port, long baud, union filedescriptor *fdp)
 {
 	LPVOID lpMsgBuf;
 	HANDLE hComPort=INVALID_HANDLE_VALUE;
@@ -129,7 +129,7 @@ static void ser_open(char * port, long baud, union filedescriptor *fdp)
 			"%s: ser_open(): network connects are currently not"
 			"implemented for Win32 environments\n",
 			progname);
-		exit(1);
+		return -1;
 	}
 
 	if (strncasecmp(port, "com", strlen("com")) == 0) {
@@ -166,7 +166,7 @@ static void ser_open(char * port, long baud, union filedescriptor *fdp)
 		fprintf(stderr, "%s: ser_open(): can't open device \"%s\": %s\n",
 				progname, port, (char*)lpMsgBuf);
 		LocalFree( lpMsgBuf );
-		exit(1);
+		return -1;
 	}
 
 	if (!SetupComm(hComPort, W32SERBUFSIZE, W32SERBUFSIZE))
@@ -174,7 +174,7 @@ static void ser_open(char * port, long baud, union filedescriptor *fdp)
 		CloseHandle(hComPort);
 		fprintf(stderr, "%s: ser_open(): can't set buffers for \"%s\"\n",
 				progname, port);
-		exit(1);
+		return -1;
 	}
 
         fdp->pfd = (void *)hComPort;
@@ -183,7 +183,7 @@ static void ser_open(char * port, long baud, union filedescriptor *fdp)
 		CloseHandle(hComPort);
 		fprintf(stderr, "%s: ser_open(): can't set com-state for \"%s\"\n",
 				progname, port);
-		exit(1);
+		return -1;
 	}
 
 	if (!serial_w32SetTimeOut(hComPort,0))
@@ -191,12 +191,13 @@ static void ser_open(char * port, long baud, union filedescriptor *fdp)
 		CloseHandle(hComPort);
 		fprintf(stderr, "%s: ser_open(): can't set initial timeout for \"%s\"\n",
 				progname, port);
-		exit(1);
+		return -1;
 	}
 
 	if (newname != 0) {
 	    free(newname);
 	}
+	return 0;
 }