diff --git a/glib/gbacktrace.c b/glib/gbacktrace.c
index 3b3b0eacb..86f884170 100644
--- a/glib/gbacktrace.c
+++ b/glib/gbacktrace.c
@@ -192,9 +192,16 @@ g_on_error_query (const gchar *prg_name)
   if (!prg_name)
     prg_name = g_get_prgname ();
 
+  /* MessageBox is allowed on UWP apps only when building against
+   * the debug CRT, which will set -D_DEBUG */
+#if defined(_DEBUG) || !defined(G_WINAPI_ONLY_APP)
   MessageBox (NULL, "g_on_error_query called, program terminating",
               (prg_name && *prg_name) ? prg_name : NULL,
               MB_OK|MB_ICONERROR);
+#else
+  printf ("g_on_error_query called, program '%s' terminating\n",
+      (prg_name && *prg_name) ? prg_name : "(null)");
+#endif
   _exit(0);
 #endif
 }
diff --git a/glib/gmessages.c b/glib/gmessages.c
index 591185605..bb1ab8f84 100644
--- a/glib/gmessages.c
+++ b/glib/gmessages.c
@@ -1358,7 +1358,9 @@ g_logv (const gchar   *log_domain,
 
           if ((test_level & G_LOG_FLAG_FATAL) && !masquerade_fatal)
             {
-#ifdef G_OS_WIN32
+              /* MessageBox is allowed on UWP apps only when building against
+               * the debug CRT, which will set -D_DEBUG */
+#if defined(G_OS_WIN32) && (defined(_DEBUG) || !defined(G_WINAPI_ONLY_APP))
               if (win32_keep_fatal_message)
                 {
                   gchar *locale_msg = g_locale_from_utf8 (fatal_msg_buf, -1, NULL, NULL, NULL);
@@ -1366,7 +1368,7 @@ g_logv (const gchar   *log_domain,
                   MessageBox (NULL, locale_msg, NULL,
                               MB_ICONERROR|MB_SETFOREGROUND);
                 }
-#endif /* !G_OS_WIN32 */
+#endif
 
               _g_log_abort (!(test_level & G_LOG_FLAG_RECURSION));
 	    }
@@ -2675,7 +2677,9 @@ handled:
   /* Abort if the message was fatal. */
   if (log_level & G_LOG_FLAG_FATAL)
     {
-#ifdef G_OS_WIN32
+      /* MessageBox is allowed on UWP apps only when building against
+       * the debug CRT, which will set -D_DEBUG */
+#if defined(G_OS_WIN32) && (defined(_DEBUG) || !defined(G_WINAPI_ONLY_APP))
       if (!g_test_initialized ())
         {
           gchar *locale_msg = NULL;
diff --git a/glib/gutils.c b/glib/gutils.c
index 62a64d912..988d0a599 100644
--- a/glib/gutils.c
+++ b/glib/gutils.c
@@ -95,28 +95,6 @@
 #ifdef G_OS_WIN32
 #  include <direct.h>
 #  include <shlobj.h>
-   /* older SDK (e.g. msvc 5.0) does not have these*/
-#  ifndef CSIDL_MYMUSIC
-#    define CSIDL_MYMUSIC 13
-#  endif
-#  ifndef CSIDL_MYVIDEO
-#    define CSIDL_MYVIDEO 14
-#  endif
-#  ifndef CSIDL_INTERNET_CACHE
-#    define CSIDL_INTERNET_CACHE 32
-#  endif
-#  ifndef CSIDL_COMMON_APPDATA
-#    define CSIDL_COMMON_APPDATA 35
-#  endif
-#  ifndef CSIDL_MYPICTURES
-#    define CSIDL_MYPICTURES 0x27
-#  endif
-#  ifndef CSIDL_COMMON_DOCUMENTS
-#    define CSIDL_COMMON_DOCUMENTS 46
-#  endif
-#  ifndef CSIDL_PROFILE
-#    define CSIDL_PROFILE 40
-#  endif
 #  include <process.h>
 #endif
 
diff --git a/gmodule/gmodule-win32.c b/gmodule/gmodule-win32.c
index 1c7226a68..795dc0938 100644
--- a/gmodule/gmodule-win32.c
+++ b/gmodule/gmodule-win32.c
@@ -39,12 +39,6 @@
 #include <sys/cygwin.h>
 #endif
 
-/* Default family is DESKTOP_APP which is DESKTOP | APP
- * We want to know when we're only building for apps */
-#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
-#define G_WINAPI_ONLY_APP
-#endif
-
 static void
 set_error (const gchar *format,
 	   ...)
@@ -133,8 +127,11 @@ find_in_any_module_using_toolhelp (const gchar *symbol_name)
   HANDLE snapshot; 
   MODULEENTRY32 me32;
 
-  gpointer p;
+  gpointer p = NULL;
 
+  /* Under UWP, Module32Next and Module32First are not available since we're
+   * not allowed to search in the address space of arbitrary loaded DLLs */
+#if !defined(G_WINAPI_ONLY_APP)
   if ((snapshot = CreateToolhelp32Snapshot (TH32CS_SNAPMODULE, 0)) == (HANDLE) -1)
     return NULL;
 
@@ -149,6 +146,7 @@ find_in_any_module_using_toolhelp (const gchar *symbol_name)
     }
 
   CloseHandle (snapshot);
+#endif
 
   return p;
 }
diff --git a/meson.build b/meson.build
index ed78359e5..d9e0a56ad 100644
--- a/meson.build
+++ b/meson.build
@@ -400,9 +400,22 @@ add_project_arguments(cc.get_supported_arguments(warning_c_args), language: 'c')
 # improve this.
 glib_link_flags = cc.get_supported_link_arguments(warning_c_link_args)
 
-# Windows Support (7+)
+# Windows SDK requirements and checks
 if host_system == 'windows'
-  glib_conf.set('_WIN32_WINNT', '0x0601')
+  # Check whether we're building for UWP apps
+  code = '''
+  #include <windows.h>
+  #if !(WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP))
+  #error "Not building for UWP"
+  #endif'''
+  if cc.compiles(code, name : 'building for UWP')
+    glib_conf.set('G_WINAPI_ONLY_APP', true)
+    # We require Windows 10+ on WinRT
+    glib_conf.set('_WIN32_WINNT', '0x0A00')
+  else
+    # We require Windows 7+ on Win32
+    glib_conf.set('_WIN32_WINNT', '0x0601')
+  endif
 endif
 
 functions = [