diff --git a/testcases/t/264-dock-criteria.t b/testcases/t/264-dock-criteria.t
index d4b3b689..1eddba71 100644
--- a/testcases/t/264-dock-criteria.t
+++ b/testcases/t/264-dock-criteria.t
@@ -19,6 +19,11 @@
 use i3test i3_config => <<EOT;
 # i3 config file (v4)
 for_window [class="dock"] move workspace current
+
+bar {
+    # Disable i3bar, which is also a dock client.
+    i3bar_command :
+}
 EOT
 
 my $ws = fresh_workspace();
diff --git a/testcases/t/504-move-workspace-to-output.t b/testcases/t/504-move-workspace-to-output.t
index b62dc219..c2d4bc9e 100644
--- a/testcases/t/504-move-workspace-to-output.t
+++ b/testcases/t/504-move-workspace-to-output.t
@@ -22,6 +22,11 @@ use i3test i3_config => <<EOT;
 font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
 
 fake-outputs 1024x768+0+0,1024x768+1024+0
+
+bar {
+    # Disable i3bar.
+    i3bar_command :
+}
 EOT
 
 # TODO: get rid of smartmatch in this test
diff --git a/testcases/t/526-reconfigure-dock.t b/testcases/t/526-reconfigure-dock.t
index 19887ac1..234fd1da 100644
--- a/testcases/t/526-reconfigure-dock.t
+++ b/testcases/t/526-reconfigure-dock.t
@@ -21,6 +21,11 @@ use i3test i3_config => <<EOT;
 font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
 
 fake-outputs 1024x768+0+0,1024x768+1024+0
+
+bar {
+    # Disable i3bar, which is also a dock client.
+    i3bar_command :
+}
 EOT
 
 my ($window, $rect);