diff --git a/include/xcb.h b/include/xcb.h
index 4d7eafa0..185163b4 100644
--- a/include/xcb.h
+++ b/include/xcb.h
@@ -108,7 +108,7 @@ void xcb_draw_rect(xcb_connection_t *conn, xcb_drawable_t drawable,
  * The truth is, however, that we will manage them.
  *
  */
-void fake_configure_notify(xcb_connection_t *conn, Rect r, xcb_window_t window);
+void fake_configure_notify(xcb_connection_t *conn, Rect r, xcb_window_t window, int border_width);
 
 /**
  * Generates a configure_notify_event with absolute coordinates (relative to
diff --git a/src/floating.c b/src/floating.c
index 0266dfa2..8d3ce4e2 100644
--- a/src/floating.c
+++ b/src/floating.c
@@ -103,6 +103,7 @@ void floating_enable(Con *con, bool automatic) {
     int deco_height = config.font.height + 5;
 
     DLOG("Original rect: (%d, %d) with %d x %d\n", con->rect.x, con->rect.y, con->rect.width, con->rect.height);
+    DLOG("Geometry = (%d, %d) with %d x %d\n", con->geometry.x, con->geometry.y, con->geometry.width, con->geometry.height);
     Rect zero = { 0, 0, 0, 0 };
     nc->rect = con->geometry;
     /* If the geometry was not set (split containers), we need to determine a
@@ -122,9 +123,13 @@ void floating_enable(Con *con, bool automatic) {
     /* add pixels for the decoration */
     /* TODO: don’t add them when the user automatically puts new windows into
      * 1pixel/borderless mode */
-    nc->rect.height += deco_height + 4;
+    nc->rect.height += deco_height + 2;
     nc->rect.width += 4;
 
+    /* Honor the X11 border */
+    nc->rect.height += con->border_width * 2;
+    nc->rect.width += con->border_width * 2;
+
     /* Some clients (like GIMP’s color picker window) get mapped
      * to (0, 0), so we push them to a reasonable position
      * (centered over their leader) */
diff --git a/src/handlers.c b/src/handlers.c
index 72e135db..b3467990 100644
--- a/src/handlers.c
+++ b/src/handlers.c
@@ -353,25 +353,27 @@ static int handle_configure_request(xcb_configure_request_event_t *event) {
             bsr.y += deco_height;
             bsr.height -= deco_height;
         }
-        con = con->parent;
+        Con *floatingcon = con->parent;
         DLOG("Container is a floating leaf node, will do that.\n");
         if (event->value_mask & XCB_CONFIG_WINDOW_X) {
-            con->rect.x = event->x + (-1) * bsr.x;
-            DLOG("proposed x = %d, new x is %d\n", event->x, con->rect.x);
+            floatingcon->rect.x = event->x + (-1) * bsr.x;
+            DLOG("proposed x = %d, new x is %d\n", event->x, floatingcon->rect.x);
         }
         if (event->value_mask & XCB_CONFIG_WINDOW_Y) {
-            con->rect.y = event->y + (-1) * bsr.y;
-            DLOG("proposed y = %d, new y is %d\n", event->y, con->rect.y);
+            floatingcon->rect.y = event->y + (-1) * bsr.y;
+            DLOG("proposed y = %d, new y is %d\n", event->y, floatingcon->rect.y);
         }
         if (event->value_mask & XCB_CONFIG_WINDOW_WIDTH) {
-            con->rect.width = event->width + (-1) * bsr.width;
-            DLOG("proposed width = %d, new width is %d\n", event->width, con->rect.width);
+            floatingcon->rect.width = event->width + (-1) * bsr.width;
+            floatingcon->rect.width += con->border_width * 2;
+            DLOG("proposed width = %d, new width is %d (x11 border %d)\n", event->width, floatingcon->rect.width, con->border_width);
         }
         if (event->value_mask & XCB_CONFIG_WINDOW_HEIGHT) {
-            con->rect.height = event->height + (-1) * bsr.height;
-            DLOG("proposed height = %d, new height is %d\n", event->height, con->rect.height);
+            floatingcon->rect.height = event->height + (-1) * bsr.height;
+            floatingcon->rect.height += con->border_width * 2;
+            DLOG("proposed height = %d, new height is %d (x11 border %d)\n", event->height, floatingcon->rect.height, con->border_width);
         }
-        floating_maybe_reassign_ws(con);
+        floating_maybe_reassign_ws(floatingcon);
         tree_render();
     }
 
diff --git a/src/xcb.c b/src/xcb.c
index b11b0ca6..09f0fb25 100644
--- a/src/xcb.c
+++ b/src/xcb.c
@@ -168,7 +168,7 @@ void xcb_draw_rect(xcb_connection_t *conn, xcb_drawable_t drawable, xcb_gcontext
  * The truth is, however, that we will manage them.
  *
  */
-void fake_configure_notify(xcb_connection_t *conn, Rect r, xcb_window_t window) {
+void fake_configure_notify(xcb_connection_t *conn, Rect r, xcb_window_t window, int border_width) {
     /* Every X11 event is 32 bytes long. Therefore, XCB will copy 32 bytes.
      * In order to properly initialize these bytes, we allocate 32 bytes even
      * though we only need less for an xcb_configure_notify_event_t */
@@ -184,7 +184,7 @@ void fake_configure_notify(xcb_connection_t *conn, Rect r, xcb_window_t window)
     generated_event->width = r.width;
     generated_event->height = r.height;
 
-    generated_event->border_width = 0;
+    generated_event->border_width = border_width;
     generated_event->above_sibling = XCB_NONE;
     generated_event->override_redirect = false;
 
@@ -211,7 +211,7 @@ void fake_absolute_configure_notify(Con *con) {
 
     DLOG("fake rect = (%d, %d, %d, %d)\n", absolute.x, absolute.y, absolute.width, absolute.height);
 
-    fake_configure_notify(conn, absolute, con->window->id);
+    fake_configure_notify(conn, absolute, con->window->id, con->border_width);
 }
 
 /*
diff --git a/testcases/t/04-floating.t b/testcases/t/04-floating.t
index d4aea828..fcf73f08 100644
--- a/testcases/t/04-floating.t
+++ b/testcases/t/04-floating.t
@@ -51,7 +51,7 @@ sleep 0.25;
 ($absolute, $top) = $window->rect;
 
 cmp_ok($absolute->{width}, '==', 80, "i3 let the width at 80");
-cmp_ok($absolute->{height}, '==', 92, "i3 let the height at 90");
+cmp_ok($absolute->{height}, '==', 90, "i3 let the height at 90");
 
 # We need to compare the position with decorations due to the way
 # we do decoration rendering (on the parent frame) in the tree branch
@@ -60,4 +60,31 @@ cmp_ok($top->{y}, '==', 19, 'i3 mapped it to y=18');
 
 $window->unmap;
 
+#####################################################################
+# check that a tiling window which is then made floating still has
+# at least the size of its initial geometry
+#####################################################################
+
+$window = $x->root->create_child(
+    class => WINDOW_CLASS_INPUT_OUTPUT,
+    rect => [ 1, 1, 80, 90],
+    background_color => '#C0C0C0',
+    #window_type => $x->atom(name => '_NET_WM_WINDOW_TYPE_UTILITY'),
+);
+
+isa_ok($window, 'X11::XCB::Window');
+
+$window->map;
+
+sleep 0.25;
+
+cmd 'floating enable';
+
+($absolute, $top) = $window->rect;
+
+cmp_ok($absolute->{width}, '==', 80, "i3 let the width at 80");
+cmp_ok($absolute->{height}, '==', 90, "i3 let the height at 90");
+
+$window->unmap;
+
 done_testing;