diff --git a/testcases/t/189-floating-constraints.t b/testcases/t/189-floating-constraints.t
index 0d3d2268..debbb0a2 100644
--- a/testcases/t/189-floating-constraints.t
+++ b/testcases/t/189-floating-constraints.t
@@ -146,6 +146,7 @@ $window = open_floating_window(rect => [ 0, 0, 100, 100 ]);
 cmd 'border none';
 cmd 'resize shrink height 80px or 80ppt';
 cmd 'resize shrink width 80px or 80ppt';
+sync_with_i3;
 $rect = $window->rect;
 is($rect->{width}, 60, 'width = 60');
 is($rect->{height}, 50, 'height = 50');
@@ -170,6 +171,7 @@ $window = open_floating_window(rect => [ 200, 200, 50, 50 ]);
 cmd 'border none';
 cmd 'resize grow height 100px or 100ppt';
 cmd 'resize grow width 100px or 100ppt';
+sync_with_i3;
 $rect = $window->rect;
 is($rect->{width}, 100, 'width = 100');
 is($rect->{height}, 100, 'height = 100');
@@ -177,6 +179,7 @@ is($rect->{height}, 100, 'height = 100');
 my $old_x = $rect->{x};
 my $old_y = $rect->{y};
 cmd 'resize grow up 10px or 10ppt';
+sync_with_i3;
 $rect = $window->rect;
 is($rect->{x}, $old_x, 'window did not move when trying to resize');
 is($rect->{y}, $old_y, 'window did not move when trying to resize');