diff --git a/dlls/vbscript/global.c b/dlls/vbscript/global.c
index ae5db24ab74..793d7c8a625 100644
--- a/dlls/vbscript/global.c
+++ b/dlls/vbscript/global.c
@@ -63,7 +63,7 @@ static IInternetHostSecurityManager *get_sec_mgr(script_ctx_t *ctx)
     return ctx->secmgr = secmgr;
 }
 
-static HRESULT return_bstr(VARIANT *res, const WCHAR *str)
+static HRESULT return_string(VARIANT *res, const WCHAR *str)
 {
     BSTR ret;
 
@@ -79,6 +79,17 @@ static HRESULT return_bstr(VARIANT *res, const WCHAR *str)
     return S_OK;
 }
 
+static HRESULT return_bstr(VARIANT *res, BSTR str)
+{
+    if(res) {
+        V_VT(res) = VT_BSTR;
+        V_BSTR(res) = str;
+    }else {
+        SysFreeString(str);
+    }
+    return S_OK;
+}
+
 static HRESULT return_short(VARIANT *res, short val)
 {
     if(res) {
@@ -137,6 +148,9 @@ static HRESULT to_int(VARIANT *v, int *ret)
         *ret = n;
         break;
     }
+    case VT_BOOL:
+        *ret = V_BOOL(v) ? -1 : 0;
+        break;
     default:
         FIXME("not supported %s\n", debugstr_variant(v));
         return E_NOTIMPL;
@@ -427,7 +441,7 @@ static HRESULT Global_Hex(vbdisp_t *This, VARIANT *arg, unsigned args_cnt, VARIA
         *ptr = '0';
     }
 
-    return return_bstr(res, ptr);
+    return return_string(res, ptr);
 }
 
 static HRESULT Global_Oct(vbdisp_t *This, VARIANT *arg, unsigned args_cnt, VARIANT *res)
@@ -1224,8 +1238,35 @@ static HRESULT Global_FormatDateTime(vbdisp_t *This, VARIANT *arg, unsigned args
 
 static HRESULT Global_WeekdayName(vbdisp_t *This, VARIANT *arg, unsigned args_cnt, VARIANT *res)
 {
-    FIXME("\n");
-    return E_NOTIMPL;
+    int weekday, first_day = 0, abbrev = 0;
+    BSTR ret;
+    HRESULT hres;
+
+    TRACE("\n");
+
+    assert(1 <= args_cnt && args_cnt <= 3);
+
+    hres = to_int(arg+args_cnt-1, &weekday);
+    if(FAILED(hres))
+        return hres;
+
+    if(args_cnt > 1) {
+        hres = to_int(arg+args_cnt-2, &abbrev);
+        if(FAILED(hres))
+            return hres;
+
+        if(args_cnt == 3) {
+            hres = to_int(arg, &first_day);
+            if(FAILED(hres))
+                return hres;
+        }
+    }
+
+    hres = VarWeekdayName(weekday, abbrev, first_day, 0, &ret);
+    if(FAILED(hres))
+        return hres;
+
+    return return_bstr(res, ret);
 }
 
 static HRESULT Global_MonthName(vbdisp_t *This, VARIANT *arg, unsigned args_cnt, VARIANT *res)
@@ -1988,7 +2029,7 @@ static const builtin_prop_t global_props[] = {
     {DISPID_GLOBAL_FORMATCURRENCY,            Global_FormatCurrency, 0, 1, 5},
     {DISPID_GLOBAL_FORMATPERCENT,             Global_FormatPercent, 0, 1, 5},
     {DISPID_GLOBAL_FORMATDATETIME,            Global_FormatDateTime, 0, 1, 2},
-    {DISPID_GLOBAL_WEEKDAYNAME,               Global_WeekdayName, 0, 3},
+    {DISPID_GLOBAL_WEEKDAYNAME,               Global_WeekdayName, 0, 1, 3},
     {DISPID_GLOBAL_MONTHNAME,                 Global_MonthName, 0, 1, 2},
     {DISPID_GLOBAL_ROUND,                     Global_Round, 0, 1, 2},
     {DISPID_GLOBAL_ESCAPE,                    Global_Escape, 0, 1},
diff --git a/dlls/vbscript/tests/api.vbs b/dlls/vbscript/tests/api.vbs
index 5efde288007..66b95a9359e 100644
--- a/dlls/vbscript/tests/api.vbs
+++ b/dlls/vbscript/tests/api.vbs
@@ -190,6 +190,7 @@ Call ok(Len(empty) = 0, "Len(empty) = " & Len(empty))
 
 Call ok(Space(1) = " ", "Space(1) = " & Space(1) & """")
 Call ok(Space(0) = "", "Space(0) = " & Space(0) & """")
+Call ok(Space(false) = "", "Space(false) = " & Space(false) & """")
 Call ok(Space(5) = "     ", "Space(5) = " & Space(5) & """")
 Call ok(Space(5.2) = "     ", "Space(5.2) = " & Space(5.2) & """")
 Call ok(Space(5.8) = "      ", "Space(5.8) = " & Space(5.8) & """")
@@ -210,4 +211,18 @@ TestRound "2", 2, "VT_R8"
 TestRound true, true, "VT_BOOL"
 TestRound false, false, "VT_BOOL"
 
+if isEnglishLang then
+    Call ok(WeekDayName(1) = "Sunday", "WeekDayName(1) = " & WeekDayName(1))
+    Call ok(WeekDayName(3) = "Tuesday", "WeekDayName(3) = " & WeekDayName(3))
+    Call ok(WeekDayName(7) = "Saturday", "WeekDayName(7) = " & WeekDayName(7))
+    Call ok(WeekDayName(1.1) = "Sunday", "WeekDayName(1.1) = " & WeekDayName(1.1))
+    Call ok(WeekDayName(1, false) = "Sunday", "WeekDayName(1, false) = " & WeekDayName(1, false))
+    Call ok(WeekDayName(1, true) = "Sun", "WeekDayName(1, true) = " & WeekDayName(1, true))
+    Call ok(WeekDayName(1, 10) = "Sun", "WeekDayName(1, 10) = " & WeekDayName(1, 10))
+    Call ok(WeekDayName(1, true, 0) = "Sun", "WeekDayName(1, true, 0) = " & WeekDayName(1, true, 0))
+    Call ok(WeekDayName(1, true, 2) = "Mon", "WeekDayName(1, true, 2) = " & WeekDayName(1, true, 2))
+    Call ok(WeekDayName(1, true, 7) = "Sat", "WeekDayName(1, true, 7) = " & WeekDayName(1, true, 7))
+    Call ok(WeekDayName(1, true, 7.1) = "Sat", "WeekDayName(1, true, 7.1) = " & WeekDayName(1, true, 7.1))
+end if
+
 Call reportSuccess()
diff --git a/dlls/vbscript/tests/run.c b/dlls/vbscript/tests/run.c
index ae590bfe172..3f68717921d 100644
--- a/dlls/vbscript/tests/run.c
+++ b/dlls/vbscript/tests/run.c
@@ -202,10 +202,10 @@ static BOOL is_lang_english(void)
         pGetThreadUILanguage = (void*)GetProcAddress(hkernel32, "GetThreadUILanguage");
         pGetUserDefaultUILanguage = (void*)GetProcAddress(hkernel32, "GetUserDefaultUILanguage");
     }
-    if (pGetThreadUILanguage)
-        return PRIMARYLANGID(pGetThreadUILanguage()) == LANG_ENGLISH;
-    if (pGetUserDefaultUILanguage)
-        return PRIMARYLANGID(pGetUserDefaultUILanguage()) == LANG_ENGLISH;
+    if (pGetThreadUILanguage && PRIMARYLANGID(pGetThreadUILanguage()) != LANG_ENGLISH)
+        return FALSE;
+    if (pGetUserDefaultUILanguage && PRIMARYLANGID(pGetUserDefaultUILanguage()) != LANG_ENGLISH)
+        return FALSE;
 
     return PRIMARYLANGID(GetUserDefaultLangID()) == LANG_ENGLISH;
 }
@@ -1906,7 +1906,7 @@ START_TEST(run)
 
     is_english = is_lang_english();
     if(!is_english)
-        skip("Skipping some tests in non-English UIs\n");
+        skip("Skipping some tests in non-English locale\n");
 
     argc = winetest_get_mainargs(&argv);