diff --git a/include/data.h b/include/data.h
index cc9fca1d..c7fcb4a5 100644
--- a/include/data.h
+++ b/include/data.h
@@ -338,6 +338,12 @@ struct Con {
         FLOATING_USER_ON = 3
     } floating;
 
+    /** This counter contains the number of UnmapNotify events for this
+     * container (or, more precisely, for its ->frame) which should be ignored.
+     * UnmapNotify events need to be ignored when they are caused by i3 itself,
+     * for example when reparenting or when unmapping the window on a workspace
+     * change. */
+    uint8_t ignore_unmap;
 
     TAILQ_ENTRY(Con) nodes;
     TAILQ_ENTRY(Con) focused;
diff --git a/src/handlers.c b/src/handlers.c
index e8c626e1..f5966db9 100644
--- a/src/handlers.c
+++ b/src/handlers.c
@@ -444,8 +444,6 @@ int handle_screen_change(void *prophs, xcb_connection_t *conn,
  */
 int handle_unmap_notify_event(void *data, xcb_connection_t *conn, xcb_unmap_notify_event_t *event) {
 
-    bool ignored = event_is_ignored(event->sequence);
-
     /* FIXME: we cannot ignore this sequence because more UnmapNotifys with the same sequence
      * numbers but different window IDs may follow */
     /* we need to ignore EnterNotify events which will be generated because a
@@ -453,14 +451,24 @@ int handle_unmap_notify_event(void *data, xcb_connection_t *conn, xcb_unmap_noti
     //add_ignore_event(event->sequence);
 
     DLOG("UnmapNotify for 0x%08x (received from 0x%08x), serial %d\n", event->window, event->event, event->sequence);
-    if (ignored) {
-        DLOG("Ignoring UnmapNotify (generated by reparenting)\n");
-        unignore_event(event->sequence);
-        return 1;
-    }
     Con *con = con_by_window_id(event->window);
     if (con == NULL) {
-        LOG("Not a managed window, ignoring\n");
+        /* This could also be an UnmapNotify for the frame. We need to
+         * decrement the ignore_unmap counter. */
+        con = con_by_frame_id(event->window);
+        if (con == NULL) {
+            LOG("Not a managed window, ignoring UnmapNotify event\n");
+            return 1;
+        }
+        if (con->ignore_unmap > 0)
+            con->ignore_unmap--;
+        DLOG("ignore_unmap = %d for frame of container %p\n", con->ignore_unmap, con);
+        return 1;
+    }
+
+    if (con->ignore_unmap > 0) {
+        DLOG("ignore_unmap = %d, dec\n", con->ignore_unmap);
+        con->ignore_unmap--;
         return 1;
     }
 
diff --git a/src/tree.c b/src/tree.c
index 7d12cab1..dac949ba 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -291,10 +291,21 @@ void level_down() {
 
 static void mark_unmapped(Con *con) {
     Con *current;
+    DLOG("marking container %p unmapped\n", con);
 
     con->mapped = false;
     TAILQ_FOREACH(current, &(con->nodes_head), nodes)
         mark_unmapped(current);
+    if (con->type == CT_WORKSPACE) {
+        TAILQ_FOREACH(current, &(con->floating_head), floating_windows) {
+            DLOG("Marking unmapped for floating %p\n", current);
+            current->mapped = false;
+            Con *child = TAILQ_FIRST(&(current->nodes_head));
+            DLOG("  unmapping floating child %p\n", child);
+            child->mapped = false;
+        }
+    }
+    DLOG("mark_unmapped done\n");
 }
 
 /*
diff --git a/src/x.c b/src/x.c
index 1ee23e64..0de6c65a 100644
--- a/src/x.c
+++ b/src/x.c
@@ -425,6 +425,10 @@ static void x_push_node(Con *con) {
 
         state->old_frame = XCB_NONE;
         state->need_reparent = false;
+
+        con->ignore_unmap++;
+        DLOG("ignore_unmap for reparenting of con %p (win 0x%08x) is now %d\n",
+                con, con->window->id, con->ignore_unmap);
     }
 
     /* map/unmap if map state changed, also ensure that the child window
@@ -442,6 +446,11 @@ static void x_push_node(Con *con) {
 
             cookie = xcb_unmap_window(conn, con->frame);
             LOG("unmapping container (serial %d)\n", cookie.sequence);
+            /* we need to increase ignore_unmap for this container (if it contains a window) and for every window "under" this one which contains a window */
+            if (con->window != NULL) {
+                con->ignore_unmap++;
+                DLOG("ignore_unmap for con %p (frame 0x%08x) now %d\n", con, con->frame, con->ignore_unmap);
+            }
             /* Ignore enter_notifies which are generated when unmapping */
             add_ignore_event(cookie.sequence);
         } else {
diff --git a/testcases/t/36-floating-unmap.t b/testcases/t/36-floating-unmap.t
new file mode 100644
index 00000000..9d122fab
--- /dev/null
+++ b/testcases/t/36-floating-unmap.t
@@ -0,0 +1,64 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+# Regression test: Floating windows were not correctly unmapped when switching
+# to a different workspace.
+
+use i3test tests => 5;
+use X11::XCB qw(:all);
+use Time::HiRes qw(sleep);
+
+BEGIN {
+    use_ok('X11::XCB::Window');
+}
+
+my $i3 = i3("/tmp/nestedcons");
+
+my $tmp = get_unused_workspace();
+$i3->command("workspace $tmp")->recv;
+
+#############################################################################
+# 1: open a floating window, get it mapped
+#############################################################################
+
+my $x = X11::XCB::Connection->new;
+
+# FIXME: we open a tiling container as long as t/37* is not done (should swap positions with t/36* then)
+my $twindow = $x->root->create_child(
+    class => WINDOW_CLASS_INPUT_OUTPUT,
+    rect => [ 0, 0, 30, 30],
+    background_color => '#C0C0C0',
+);
+
+isa_ok($twindow, 'X11::XCB::Window');
+
+$twindow->map;
+
+sleep 0.25;
+
+# Create a floating window which is smaller than the minimum enforced size of i3
+my $window = $x->root->create_child(
+    class => WINDOW_CLASS_INPUT_OUTPUT,
+    rect => [ 0, 0, 30, 30],
+    background_color => '#C0C0C0',
+    # replace the type with 'utility' as soon as the coercion works again in X11::XCB
+    window_type => $x->atom(name => '_NET_WM_WINDOW_TYPE_UTILITY'),
+);
+
+isa_ok($window, 'X11::XCB::Window');
+
+$window->map;
+
+sleep 0.25;
+
+ok($window->mapped, 'Window is mapped');
+
+# switch to a different workspace, see if the window is still mapped?
+
+my $otmp = get_unused_workspace();
+$i3->command("workspace $otmp")->recv;
+
+sleep 0.25;
+
+ok(!$window->mapped, 'Window is not mapped after switching ws');
+
+$i3->command("nop testcase done")->recv;