diff --git a/include/data.h b/include/data.h
index 4f7983dc..13ce08b4 100644
--- a/include/data.h
+++ b/include/data.h
@@ -239,6 +239,7 @@ struct Match {
     char *class;
     char *instance;
     xcb_window_t id;
+    Con *con_id;
     bool floating;
 
     enum { M_GLOBAL, M_OUTPUT, M_WORKSPACE } levels;
diff --git a/src/cmdparse.l b/src/cmdparse.l
index 684a588c..079aa8f9 100644
--- a/src/cmdparse.l
+++ b/src/cmdparse.l
@@ -95,11 +95,14 @@ none                            { return TOK_NONE; }
 mode                            { return TOK_MODE; }
 tiling                          { return TOK_TILING; }
 floating                        { return TOK_FLOATING; }
-workspace                       { return TOK_WORKSPACE; }
+workspace                       { BEGIN(WANT_WS_STRING); return TOK_WORKSPACE; }
 focus                           { return TOK_FOCUS; }
 move                            { return TOK_MOVE; }
+open                            { return TOK_OPEN; }
 
 class                           { BEGIN(WANT_QSTRING); return TOK_CLASS; }
+id                              { BEGIN(WANT_QSTRING); return TOK_ID; }
+con_id                          { BEGIN(WANT_QSTRING); return TOK_CON_ID; }
 
 .                               { return (int)yytext[0]; }
 
diff --git a/src/cmdparse.y b/src/cmdparse.y
index eb5ab71f..81dd148d 100644
--- a/src/cmdparse.y
+++ b/src/cmdparse.y
@@ -109,8 +109,11 @@ void parse_cmd(const char *new) {
 %token TOK_WORKSPACE "workspace"
 %token TOK_FOCUS "focus"
 %token TOK_MOVE "move"
+%token TOK_OPEN "open"
 
 %token TOK_CLASS "class"
+%token TOK_ID "id"
+%token TOK_CON_ID "con_id"
 
 %token WHITESPACE "<whitespace>"
 %token STR "<string>"
@@ -156,9 +159,6 @@ matchstart:
         /* copy all_cons */
         Con *con;
         TAILQ_FOREACH(con, &all_cons, all_cons) {
-            if (con->window == NULL)
-                continue;
-
             owindow *ow = smalloc(sizeof(owindow));
             ow->con = con;
             TAILQ_INSERT_TAIL(&owindows, ow, owindows);
@@ -184,12 +184,22 @@ matchend:
             next = TAILQ_NEXT(next, owindows);
 
             printf("checking if con %p / %s matches\n", current->con, current->con->name);
-            if (match_matches_window(&current_match, current->con->window)) {
-                printf("matches!\n");
-                TAILQ_INSERT_TAIL(&owindows, current, owindows);
+            if (current_match.con_id != NULL) {
+                if (current_match.con_id == current->con) {
+                    printf("matches container!\n");
+                    TAILQ_INSERT_TAIL(&owindows, current, owindows);
+
+                }
             } else {
-                printf("doesnt match\n");
-                free(current);
+                if (current->con->window == NULL)
+                    continue;
+                if (match_matches_window(&current_match, current->con->window)) {
+                    printf("matches window!\n");
+                    TAILQ_INSERT_TAIL(&owindows, current, owindows);
+                } else {
+                    printf("doesnt match\n");
+                    free(current);
+                }
             }
         }
 
@@ -206,6 +216,13 @@ criteria:
         printf("criteria: class = %s\n", $<string>3);
         current_match.class = $<string>3;
     }
+    | TOK_CON_ID '=' STR
+    {
+        printf("criteria: id = %s\n", $<string>3);
+        /* TODO: correctly parse number */
+        current_match.con_id = atoi($<string>3);
+        printf("id as int = %d\n", current_match.con_id);
+    }
     ;
 
 operations:
@@ -226,9 +243,11 @@ operation:
     | mode
     | workspace
     | move*/
+    | workspace
     | attach
     | focus
     | kill
+    | open
     ;
 
 exec:
@@ -265,10 +284,32 @@ kill:
         owindow *current;
 
         printf("killing!\n");
+        /* TODO: check if the match is empty, not if the result is empty */
+        if (TAILQ_EMPTY(&owindows))
+            tree_close(focused);
+        else {
         TAILQ_FOREACH(current, &owindows, owindows) {
             printf("matching: %p / %s\n", current->con, current->con->name);
             tree_close(current->con);
         }
+        }
 
     }
     ;
+
+workspace:
+    TOK_WORKSPACE WHITESPACE STR
+    {
+        printf("should switch to workspace %s\n", $<string>3);
+        workspace_show($<string>3);
+        free($<string>3);
+    }
+    ;
+
+open:
+    TOK_OPEN
+    {
+        printf("opening new container\n");
+        tree_open_con(NULL);
+    }
+    ;
diff --git a/src/ipc.c b/src/ipc.c
index 0412bdae..704c0d47 100644
--- a/src/ipc.c
+++ b/src/ipc.c
@@ -114,7 +114,7 @@ IPC_HANDLER(command) {
          * message_size bytes out of the buffer */
         char *command = scalloc(message_size);
         strncpy(command, (const char*)message, message_size);
-        parse_command((const char*)command);
+        parse_cmd((const char*)command);
         free(command);
 
         /* For now, every command gets a positive acknowledge
diff --git a/testcases/t/18-openkill.t b/testcases/t/18-openkill.t
index e13ca873..935523d4 100644
--- a/testcases/t/18-openkill.t
+++ b/testcases/t/18-openkill.t
@@ -3,7 +3,8 @@
 #
 # Tests whether opening an empty container and killing it again works
 #
-use Test::More tests => 3;
+use Test::More tests => 6;
+use Data::Dumper;
 use FindBin;
 use lib "$FindBin::Bin/lib";
 use i3test;
@@ -25,4 +26,25 @@ ok(@{get_ws_content($tmp)} == 1, 'container opened');
 $i3->command("kill")->recv;
 ok(@{get_ws_content($tmp)} == 0, 'container killed');
 
+##############################################################
+# open two containers and kill the one which is not focused
+# by its ID to test if the parser correctly matches the window
+##############################################################
+
+$i3->command('open')->recv;
+$i3->command('open')->recv;
+ok(@{get_ws_content($tmp)} == 2, 'two containers opened');
+
+my $content = get_ws_content($tmp);
+# TODO: get the focused window, don’t assume that it is
+# the latest one
+my $id = $content->[0]->{id};
+diag('id of not focused = ' . $id);
+
+$i3->command("[con_id=\"$id\"] kill")->recv;
+
+$content = get_ws_content($tmp);
+ok(@{$content} == 1, 'one container killed');
+ok($content->[0]->{id} != $id, 'correct window killed');
+
 diag( "Testing i3, Perl $], $^X" );