diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0ce33f237e8..1ac3b55e484 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2019-02-06  John Baldwin  <jhb@FreeBSD.org>
+
+	* fbsd-nat.c (fbsd_fetch_cmdline): Join arguments with spaces.
+
 2019-02-05  Tom Tromey  <tom@tromey.com>
 
 	* target.c (target_stack::unpush): Move assertion earlier.
diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index 712f9d3b7b8..184d63939f4 100644
--- a/gdb/fbsd-nat.c
+++ b/gdb/fbsd-nat.c
@@ -231,6 +231,13 @@ fbsd_fetch_cmdline (pid_t pid)
   if (sysctl (mib, 4, cmdline.get (), &len, NULL, 0) == -1)
     return nullptr;
 
+  /* Join the arguments with spaces to form a single string.  */
+  char *cp = cmdline.get ();
+  for (size_t i = 0; i < len - 1; i++)
+    if (cp[i] == '\0')
+      cp[i] = ' ';
+  cp[len - 1] = '\0';
+
   return cmdline;
 }