diff --git a/src/cfgparse.y b/src/cfgparse.y
index 6e59c87c..2c796af1 100644
--- a/src/cfgparse.y
+++ b/src/cfgparse.y
@@ -934,7 +934,14 @@ bar:
     {
         printf("\t new bar configuration finished, saving.\n");
         /* Generate a unique ID for this bar */
-        current_bar.id = sstrdup("foo"); /* TODO */
+        current_bar.id = sstrdup("bar-XXXXXX");
+        /* This works similar to mktemp in that it replaces the last six X with
+         * random letters, but without the restriction that the given buffer
+         * has to contain a valid path name. */
+        char *x = current_bar.id + strlen("bar-");
+        while (*x != '\0') {
+            *(x++) = (rand() % 26) + 'a';
+        }
 
         /* Copy the current (static) structure into a dynamically allocated
          * one, then cleanup our static one. */
diff --git a/src/main.c b/src/main.c
index ffdc1fd3..832d7f1b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -217,6 +217,8 @@ int main(int argc, char *argv[]) {
     if (!isatty(fileno(stdout)))
         setbuf(stdout, NULL);
 
+    srand(time(NULL));
+
     init_logging();
 
     start_argv = argv;
diff --git a/testcases/t/177-bar-config.t b/testcases/t/177-bar-config.t
index 98eb4edd..c7cf2843 100644
--- a/testcases/t/177-bar-config.t
+++ b/testcases/t/177-bar-config.t
@@ -99,9 +99,9 @@ $i3 = i3(get_socket_path(0));
 $bars = $i3->get_bar_config()->recv;
 is(@$bars, 1, 'one bar configured');
 
-my $bar_id = shift @$bars;
+$bar_id = shift @$bars;
 
-my $bar_config = $i3->get_bar_config($bar_id)->recv;
+$bar_config = $i3->get_bar_config($bar_id)->recv;
 is($bar_config->{status_command}, 'i3status --bar', 'status_command correct');
 ok($bar_config->{verbose}, 'verbose on');
 ok(!$bar_config->{workspace_buttons}, 'workspace buttons disabled');
@@ -127,4 +127,39 @@ is_deeply($bar_config->{colors},
 
 exit_gracefully($pid);
 
+#####################################################################
+# ensure that multiple bars get different IDs
+#####################################################################
+
+$config = <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+bar {
+    # Start a default instance of i3bar which provides workspace buttons.
+    # Additionally, i3status will provide a statusline.
+    status_command i3status --bar
+
+    output HDMI1
+}
+
+bar {
+    output VGA1
+}
+EOT
+
+$pid = launch_with_config($config);
+
+$i3 = i3(get_socket_path(0));
+$bars = $i3->get_bar_config()->recv;
+is(@$bars, 2, 'two bars configured');
+isnt($bars->[0], $bars->[1], 'bar IDs are different');
+
+my $bar1_config = $i3->get_bar_config($bars->[0])->recv;
+my $bar2_config = $i3->get_bar_config($bars->[1])->recv;
+
+isnt($bar1_config->{outputs}, $bar2_config->{outputs}, 'outputs different');
+
+exit_gracefully($pid);
+
 done_testing;