diff --git a/c_src/alcove.c b/c_src/alcove.c
index 4bb45a5..2a95366 100644
--- a/c_src/alcove.c
+++ b/c_src/alcove.c
@@ -88,16 +88,21 @@ main(int argc, char *argv[])
     if (!ap)
         erl_err_sys("calloc");
 
-    ap->child = calloc(ALCOVE_MAX_CHILD, sizeof(alcove_child_t));
-    if (!ap->child)
-        erl_err_sys("calloc");
-
     act.sa_handler = sighandler;
     if (sigaction(SIGCHLD, &act, NULL) < 0)
         erl_err_sys("sigaction");
 
-    while ( (ch = getopt(argc, argv, "hv")) != -1) {
+    /* 3 pipes per child */
+    ap->maxchild = FD_SETSIZE / 3 - 3;
+
+    while ( (ch = getopt(argc, argv, "am:hv")) != -1) {
         switch (ch) {
+            case 'm': {
+                u_int16_t n = (u_int16_t)atoi(optarg);
+
+                if (n < ap->maxchild)
+                    ap->maxchild = n;
+            }
             case 'v':
                 ap->verbose++;
                 break;
@@ -107,6 +112,10 @@ main(int argc, char *argv[])
         }
     }
 
+    ap->child = calloc(ap->maxchild, sizeof(alcove_child_t));
+    if (!ap->child)
+        erl_err_sys("calloc");
+
     alcove_ctl(ap);
     exit(0);
 }
@@ -119,7 +128,7 @@ alcove_ctl(alcove_state_t *ap)
 
     erl_init(NULL, 0);
 
-    (void)memset(ap->child, 0, sizeof(alcove_child_t) * ALCOVE_MAX_CHILD);
+    (void)memset(ap->child, 0, sizeof(alcove_child_t) * ap->maxchild);
     sigcaught = 0;
 
     for ( ; ; ) {
@@ -380,7 +389,7 @@ pid_foreach(alcove_state_t *ap, pid_t pid, void *arg1, void *arg2,
     int i = 0;
     int rv = 0;
 
-    for (i = 0; i < ALCOVE_MAX_CHILD; i++) {
+    for (i = 0; i < ap->maxchild; i++) {
         if ((*comp)(ap->child[i].pid, pid) == 0)
             continue;
 
@@ -555,6 +564,7 @@ usage(alcove_state_t *ap)
             __progname, ALCOVE_VERSION);
     (void)fprintf(stderr,
             "usage: %s <options>\n"
+            "   -m <num>        max children\n"
             "   -v              verbose mode\n",
             __progname
             );
diff --git a/c_src/alcove.h b/c_src/alcove.h
index 74024df..663cd28 100644
--- a/c_src/alcove.h
+++ b/c_src/alcove.h
@@ -46,11 +46,10 @@ typedef struct {
     int fderr;
 } alcove_child_t;
 
-#define ALCOVE_MAX_CHILD    16
-
 typedef struct {
     u_int32_t opt;
     u_int8_t verbose;
+    u_int16_t maxchild;
     alcove_child_t *child;
 } alcove_state_t;
 
diff --git a/c_src/alcove_call.c b/c_src/alcove_call.c
index 9b875b5..5b0e164 100644
--- a/c_src/alcove_call.c
+++ b/c_src/alcove_call.c
@@ -26,6 +26,8 @@
 
 #include <sys/types.h>
 
+static int cons_pid(alcove_child_t *c, void *arg1, void *arg2);
+
     ETERM *
 alcove_call(alcove_state_t *ap, u_int32_t call, ETERM *arg)
 {
@@ -52,15 +54,7 @@ alcove_version(alcove_state_t *ap, ETERM *arg)
 alcove_pid(alcove_state_t *ap, ETERM *arg)
 {
     ETERM *t = erl_mk_empty_list();
-    int i = 0;
-
-    for (i = 0; i < ALCOVE_MAX_CHILD; i++) {
-        if (ap->child[i].pid <= 0)
-            continue;
-
-        t = erl_cons(erl_mk_int(ap->child[i].pid), t);
-    }
-
+    (void)pid_foreach(ap, 0, &t, NULL, pid_not_equal, cons_pid);
     return t;
 }
 
@@ -114,3 +108,11 @@ alcove_free_argv(char **argv)
 
     free(argv);
 }
+
+    static int
+cons_pid(alcove_child_t *c, void *arg1, void *arg2)
+{
+    ETERM **t = arg1;
+    *t = erl_cons(erl_mk_int(c->pid), *t);
+    return 1;
+}
diff --git a/src/alcove_drv.erl b/src/alcove_drv.erl
index 4bc2ea9..d5062ba 100644
--- a/src/alcove_drv.erl
+++ b/src/alcove_drv.erl
@@ -325,25 +325,21 @@ getopts(Options) when is_list(Options) ->
     Exec = proplists:get_value(exec, Options, ""),
     Progname = proplists:get_value(progname, Options, progname()),
 
-    Options1 = proplists:substitute_aliases([{ns, namespace}], Options),
-
-    Options2 = lists:map(fun
+    Options1 = lists:map(fun
                     (verbose) ->
                         {verbose, 1};
-                    ({Tag, [H|_] = N}) when is_atom(Tag), (is_list(H) orelse is_binary(H)) ->
-                        [{Tag, X} || X <- N];
                     (N) when is_atom(N) ->
                         {N, true};
                     ({_,_} = N) ->
                         N
-                end, Options1),
+                end, Options),
 
-    Switches = lists:append([ optarg(N) || N <- lists:flatten(Options2) ]),
+    Switches = lists:append([ optarg(N) || N <- Options1 ]),
     [Cmd|Argv] = [ N || N <- string:tokens(Exec, " ") ++ [Progname|Switches], N /= ""],
     [find_executable(Cmd)|Argv].
 
 optarg({verbose, Arg})          -> switch(string:copies("v", Arg));
-optarg({namespace, Arg})        -> switch("n", Arg);
+optarg({maxchild, Arg})         -> switch("m", Arg);
 optarg(_)                       -> "".
 
 switch(Switch) ->
@@ -352,7 +348,7 @@ switch(Switch) ->
 switch(Switch, Arg) when is_binary(Arg) ->
     switch(Switch, binary_to_list(Arg));
 switch(Switch, Arg) ->
-    [lists:concat(["-", Switch]), Arg].
+    [lists:concat(["-", Switch, " ", Arg])].
 
 find_executable(Exe) ->
     case os:find_executable(Exe) of
diff --git a/test/alcove_tests.erl b/test/alcove_tests.erl
index 8f6eb14..63e49e5 100644
--- a/test/alcove_tests.erl
+++ b/test/alcove_tests.erl
@@ -51,7 +51,7 @@ run(State) ->
     ].
 
 start() ->
-    Port = alcove_drv:start([{exec, "sudo"}]),
+    Port = alcove_drv:start([{exec, "sudo"}, {maxchild, 16}]),
     case os:type() of
         {unix,linux} = OS ->
             Flags = alcove:define(Port, clone, [