diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 250b327375..6e05b5e017 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+Sun Dec  3 02:28:26 2000  Andrew Cagney  <cagney@b1.cygnus.com>
+
+	* ser-pipe.c (pipe_open): Only use vfork when available.
+	* fork-child.c (fork_inferior): Fix #ifdef HAVE_VFORK test.
+	(clone_and_follow_inferior): Ditto.
+
+	* configure.in (AC_CHECK_FUNCS): Check for vfork.
+	* configure, config.in: Regenerate.
+
 Sun Dec  3 01:54:49 2000  Andrew Cagney  <cagney@b1.cygnus.com>
 
 	* ser-unix.c (wait_for): Initialize the FD_SET before every select
diff --git a/gdb/config.in b/gdb/config.in
index bfb15cd3ef..f6f00318b8 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -225,6 +225,9 @@
 /* Define if you have the strchr function.  */
 #undef HAVE_STRCHR
 
+/* Define if you have the vfork function.  */
+#undef HAVE_VFORK
+
 /* Define if you have the <argz.h> header file.  */
 #undef HAVE_ARGZ_H
 
diff --git a/gdb/configure b/gdb/configure
index f02de34d38..6786629c79 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -3557,7 +3557,7 @@ EOF
 fi
 
 
-for ac_func in setpgid sbrk sigaction isascii bzero bcopy btowc poll sigprocmask
+for ac_func in setpgid sbrk sigaction isascii bzero bcopy btowc poll sigprocmask vfork
 do
 echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
 echo "configure:3564: checking for $ac_func" >&5
diff --git a/gdb/configure.in b/gdb/configure.in
index 2b14ac308c..eb5a11f95b 100644
--- a/gdb/configure.in
+++ b/gdb/configure.in
@@ -129,7 +129,7 @@ AC_HEADER_STAT
 
 AC_C_CONST
 
-AC_CHECK_FUNCS(setpgid sbrk sigaction isascii bzero bcopy btowc poll sigprocmask)
+AC_CHECK_FUNCS(setpgid sbrk sigaction isascii bzero bcopy btowc poll sigprocmask vfork)
 AC_FUNC_ALLOCA
 
 # See if machine/reg.h supports the %fs and %gs i386 segment registers.
diff --git a/gdb/fork-child.c b/gdb/fork-child.c
index 147a59fd77..e97f451bce 100644
--- a/gdb/fork-child.c
+++ b/gdb/fork-child.c
@@ -244,13 +244,13 @@ fork_inferior (char *exec_file, char *allargs, char **env,
   if (pre_trace_fun != NULL)
     (*pre_trace_fun) ();
 
-#if defined(USG) && !defined(HAVE_VFORK)
-  pid = fork ();
-#else
+#ifdef HAVE_VFORK
   if (debug_fork)
     pid = fork ();
   else
     pid = vfork ();
+#else
+  pid = fork ();
 #endif
 
   if (pid < 0)
@@ -416,13 +416,13 @@ clone_and_follow_inferior (int child_pid, int *followed_child)
     error ("error getting pipe for handoff semaphore");
 
   /* Clone the debugger. */
-#if defined(USG) && !defined(HAVE_VFORK)
-  debugger_pid = fork ();
-#else
+#ifdef HAVE_VFORK
   if (debug_fork)
     debugger_pid = fork ();
   else
     debugger_pid = vfork ();
+#else
+  debugger_pid = fork ();
 #endif
 
   if (debugger_pid < 0)
diff --git a/gdb/ser-pipe.c b/gdb/ser-pipe.c
index a510bff8da..fd073c2e0a 100644
--- a/gdb/ser-pipe.c
+++ b/gdb/ser-pipe.c
@@ -64,7 +64,11 @@ pipe_open (serial_t scb, const char *name)
   if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
     return -1;
 
+#ifdef HAVE_VFORK
   pid = vfork ();
+#else
+  pid = fork ();
+#endif
   
   /* Error. */
   if (pid == -1)