diff --git a/meson.build b/meson.build
index 5bc8fcb..e5ed47b 100644
--- a/meson.build
+++ b/meson.build
@@ -29,8 +29,8 @@ glib_min_version='>=2.48'
 glib_min_version_symbol='GLIB_VERSION_2_48'
 
 # Keep these two definitions in agreement.
-gtk_min_version='>=3.12'
-gtk_min_version_symbol='GDK_VERSION_3_12'
+gtk_min_version='>=3.18'
+gtk_min_version_symbol='GDK_VERSION_3_18'
 
 libxml_min_version='>=2.6.0'
 libvirt_min_version='>=1.2.8'
diff --git a/src/resources/ui/remote-viewer-connect.ui b/src/resources/ui/remote-viewer-connect.ui
index b2f3f09..53174b0 100644
--- a/src/resources/ui/remote-viewer-connect.ui
+++ b/src/resources/ui/remote-viewer-connect.ui
@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.18.3 -->
 <interface>
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkWindow" id="remote-viewer-connection-window">
     <property name="can_focus">False</property>
     <property name="title" translatable="yes">Connection details</property>
diff --git a/src/resources/ui/remote-viewer-iso-list.ui b/src/resources/ui/remote-viewer-iso-list.ui
index ab1bdc4..60835bc 100644
--- a/src/resources/ui/remote-viewer-iso-list.ui
+++ b/src/resources/ui/remote-viewer-iso-list.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.20.0 -->
 <interface>
-  <requires lib="gtk+" version="3.16"/>
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkListStore" id="liststore">
     <columns>
       <!-- column-name selected -->
diff --git a/src/resources/ui/virt-viewer-about.ui b/src/resources/ui/virt-viewer-about.ui
index 25b2165..9495657 100644
--- a/src/resources/ui/virt-viewer-about.ui
+++ b/src/resources/ui/virt-viewer-about.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.36.0 -->
 <interface>
-  <requires lib="gtk+" version="3.0"/>
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkAboutDialog" id="about">
     <property name="can_focus">False</property>
     <property name="border_width">5</property>
diff --git a/src/resources/ui/virt-viewer-auth.ui b/src/resources/ui/virt-viewer-auth.ui
index 2920780..0ceb624 100644
--- a/src/resources/ui/virt-viewer-auth.ui
+++ b/src/resources/ui/virt-viewer-auth.ui
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <!-- interface-requires gtk+ 2.12 -->
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkDialog" id="auth">
     <property name="can_focus">False</property>
     <property name="border_width">5</property>
diff --git a/src/resources/ui/virt-viewer-file-transfer-dialog.ui b/src/resources/ui/virt-viewer-file-transfer-dialog.ui
index f71e174..1046fa2 100644
--- a/src/resources/ui/virt-viewer-file-transfer-dialog.ui
+++ b/src/resources/ui/virt-viewer-file-transfer-dialog.ui
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <requires lib="gtk+" version="3.10"/>
-  <!-- interface-naming-policy project-wide -->
+  <requires lib="gtk+" version="3.18"/>
   <template class="VirtViewerFileTransferDialog" parent="GtkDialog">
     <property name="default_width">400</property>
     <property name="can_focus">False</property>
diff --git a/src/resources/ui/virt-viewer-guest-details.ui b/src/resources/ui/virt-viewer-guest-details.ui
index 209272f..38668a9 100644
--- a/src/resources/ui/virt-viewer-guest-details.ui
+++ b/src/resources/ui/virt-viewer-guest-details.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.16.0 on Thu Jan 16 16:13:38 2014 -->
 <interface>
-  <!-- interface-requires gtk+ 3.0 -->
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkDialog" id="guestdetailsdialog">
     <property name="can_focus">False</property>
     <property name="title" translatable="yes">Guest Details</property>
diff --git a/src/resources/ui/virt-viewer-preferences.ui b/src/resources/ui/virt-viewer-preferences.ui
index 0b88da4..cc43344 100644
--- a/src/resources/ui/virt-viewer-preferences.ui
+++ b/src/resources/ui/virt-viewer-preferences.ui
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <!-- interface-requires gtk+ 2.6 -->
-  <!-- interface-naming-policy toplevel-contextual -->
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkDialog" id="preferences">
     <property name="can_focus">False</property>
     <property name="border_width">5</property>
diff --git a/src/resources/ui/virt-viewer-vm-connection.ui b/src/resources/ui/virt-viewer-vm-connection.ui
index cff1797..1b50640 100644
--- a/src/resources/ui/virt-viewer-vm-connection.ui
+++ b/src/resources/ui/virt-viewer-vm-connection.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.36.0 -->
 <interface>
-  <requires lib="gtk+" version="3.0"/>
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkDialog" id="vm-connection-dialog">
     <property name="can_focus">False</property>
     <property name="border_width">5</property>
diff --git a/src/resources/ui/virt-viewer.ui b/src/resources/ui/virt-viewer.ui
index d0452eb..d369301 100644
--- a/src/resources/ui/virt-viewer.ui
+++ b/src/resources/ui/virt-viewer.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.20.0 -->
 <interface>
-  <requires lib="gtk+" version="3.0"/>
+  <requires lib="gtk+" version="3.18"/>
   <object class="GtkAccelGroup" id="accelgroup"/>
   <object class="GtkApplicationWindow" id="viewer">
     <property name="can_focus">False</property>
diff --git a/src/virt-viewer-window.c b/src/virt-viewer-window.c
index 85fe9d2..19b39c9 100644
--- a/src/virt-viewer-window.c
+++ b/src/virt-viewer-window.c
@@ -604,19 +604,13 @@ virt_viewer_window_enter_fullscreen(VirtViewerWindow *self, gint monitor)
     }
     virt_viewer_window_move_to_monitor(self);
 
-#if GTK_CHECK_VERSION(3, 18, 0)
     if (monitor == -1) {
         // just go fullscreen on the current monitor
         gtk_window_fullscreen(GTK_WINDOW(self->window));
     } else {
-G_GNUC_BEGIN_IGNORE_DEPRECATIONS
         gtk_window_fullscreen_on_monitor(GTK_WINDOW(self->window),
                                          gdk_screen_get_default(), monitor);
-G_GNUC_END_IGNORE_DEPRECATIONS
     }
-#else
-        gtk_window_fullscreen(GTK_WINDOW(self->window));
-#endif /* GTK_CHECK_VERSION */
 }
 
 #define MAX_KEY_COMBO 4