diff --git a/dlls/usp10/tests/usp10.c b/dlls/usp10/tests/usp10.c
index d04b536bb4a..57f3c263fbf 100644
--- a/dlls/usp10/tests/usp10.c
+++ b/dlls/usp10/tests/usp10.c
@@ -78,6 +78,8 @@ static inline void _test_items_ok(LPCWSTR string, DWORD cchString,
             todo_wine winetest_ok(outpItems[x].a.s.uBidiLevel == items[x].uBidiLevel, "%i:Wrong BidiLevel\n",x);
         else
             winetest_ok(outpItems[x].a.s.uBidiLevel == items[x].uBidiLevel, "%i:Wrong BidiLevel(%i)\n",x,outpItems[x].a.s.uBidiLevel);
+        if (x != outnItems)
+            winetest_ok(outpItems[x].a.eScript != SCRIPT_UNDEFINED, "%i: Undefined script\n",x);
     }
 }
 
@@ -90,6 +92,10 @@ static void test_ScriptItemize( void )
     static const itemTest t11[2] = {{{0,0,0,0},0,0,0,0},{{0,0,0,0},4,0,0,0}};
     static const itemTest t12[2] = {{{0,0,0,0},0,0,0,2},{{0,0,0,0},4,0,0,0}};
 
+    static const WCHAR test1b[] = {' ', ' ', ' ', ' ',0};
+    static const itemTest t1b1[2] = {{{0,0,0,0},0,0,0,0},{{0,0,0,0},4,0,0,0}};
+    static const itemTest t1b2[2] = {{{0,0,0,0},0,1,1,1},{{0,0,0,0},4,0,0,0}};
+
     /* Arabic, English*/
     static const WCHAR test2[] = {'1','2','3','-','5','2',0x064a,0x064f,0x0633,0x0627,0x0648,0x0650,0x064a,'7','1','.',0};
     static const itemTest t21[7] = {{{0,0,0,0},0,0,0,0},{{0,0,0,0},3,0,0,0},{{0,0,0,0},4,0,0,0},{{0,0,0,0},6,1,1,1},{{0,0,0,0},13,0,0,0},{{0,0,0,0},15,0,0,0},{{0,0,0,0},16,0,0,0}};
@@ -101,6 +107,20 @@ static void test_ScriptItemize( void )
     static const itemTest t2b2[5] = {{{0,0,0,0},0,0,0,2},{{0,0,0,0},3,0,0,2},{{0,0,0,0},4,0,0,2},{{0,0,0,0},7,1,1,1},{{0,0,0,0},11,0,0,0}};
     static const itemTest t2b3[3] = {{{0,0,0,0},0,0,0,2},{{0,0,0,0},7,1,1,1},{{0,0,0,0},11,0,0,0}};
 
+    /* leading space */
+    static const WCHAR test2c[] = {' ',0x0621,0x0623,0x0624,'A','B','C','-','D','E','F',0};
+    static const itemTest t2c1[5] = {{{0,0,0,0},0,1,1,1},{{0,0,0,0},4,0,0,0},{{0,0,0,0},7,0,0,0},{{0,0,0,0},8,0,0,0},{{0,0,0,0},11,0,0,0}};
+    static const itemTest t2c2[6] = {{{0,0,0,0},0,0,0,0},{{0,0,0,0},1,1,1,1},{{0,0,0,0},4,0,0,0},{{0,0,0,0},7,0,0,0},{{0,0,0,0},8,0,0,0},{{0,0,0,0},11,0,0,0}};
+    static const itemTest t2c3[5] = {{{0,0,0,0},0,1,1,1},{{0,0,0,0},4,0,0,2},{{0,0,0,0},7,0,0,2},{{0,0,0,0},8,0,0,2},{{0,0,0,0},11,0,0,0}};
+    static const itemTest t2c4[3] = {{{0,0,0,0},0,1,1,1},{{0,0,0,0},4,0,0,2},{{0,0,0,0},11,0,0,0}};
+
+    /* trailing space */
+    static const WCHAR test2d[] = {'A','B','C','-','D','E','F',0x0621,0x0623,0x0624,' ',0};
+    static const itemTest t2d1[5] = {{{0,0,0,0},0,0,0,0},{{0,0,0,0},3,0,0,0},{{0,0,0,0},4,0,0,0},{{0,0,0,0},7,1,1,1},{{0,0,0,0},11,0,0,0}};
+    static const itemTest t2d2[6] = {{{0,0,0,0},0,0,0,0},{{0,0,0,0},3,0,0,0},{{0,0,0,0},4,0,0,0},{{0,0,0,0},7,1,1,1},{{0,0,0,0},10,0,0,0},{{0,0,0,0},11,0,0,0}};
+    static const itemTest t2d3[5] = {{{0,0,0,0},0,0,0,2},{{0,0,0,0},3,0,0,2},{{0,0,0,0},4,0,0,2},{{0,0,0,0},7,1,1,1},{{0,0,0,0},11,0,0,0}};
+    static const itemTest t2d4[3] = {{{0,0,0,0},0,0,0,2},{{0,0,0,0},7,1,1,1},{{0,0,0,0},11,0,0,0}};
+
     /* Thai */
     static const WCHAR test3[] =
 {0x0e04,0x0e27,0x0e32,0x0e21,0x0e1e,0x0e22,0x0e32,0x0e22,0x0e32, 0x0e21
@@ -168,8 +188,11 @@ static void test_ScriptItemize( void )
     ok (hr == E_INVALIDARG, "ScriptItemize should return E_INVALIDARG if cInChars is 0\n");
 
     test_items_ok(test1,4,NULL,NULL,1,t11,FALSE,0);
+    test_items_ok(test1b,4,NULL,NULL,1,t1b1,FALSE,0);
     test_items_ok(test2,16,NULL,NULL,6,t21,FALSE,0);
     test_items_ok(test2b,11,NULL,NULL,4,t2b1,FALSE,0);
+    test_items_ok(test2c,11,NULL,NULL,4,t2c1,FALSE,0);
+    test_items_ok(test2d,11,NULL,NULL,4,t2d1,FALSE,0);
     test_items_ok(test3,41,NULL,NULL,1,t31,FALSE,0);
     test_items_ok(test4,12,NULL,NULL,5,t41,FALSE,0);
     test_items_ok(test5,38,NULL,NULL,1,t51,FALSE,0);
@@ -181,8 +204,11 @@ static void test_ScriptItemize( void )
 
     State.uBidiLevel = 0;
     test_items_ok(test1,4,&Control,&State,1,t11,FALSE,0);
+    test_items_ok(test1b,4,&Control,&State,1,t1b1,FALSE,0);
     test_items_ok(test2,16,&Control,&State,4,t22,FALSE,0);
     test_items_ok(test2b,11,&Control,&State,4,t2b1,FALSE,0);
+    test_items_ok(test2c,11,&Control,&State,5,t2c2,FALSE,0);
+    test_items_ok(test2d,11,&Control,&State,5,t2d2,FALSE,0);
     test_items_ok(test3,41,&Control,&State,1,t31,FALSE,0);
     test_items_ok(test4,12,&Control,&State,5,t41,FALSE,0);
     test_items_ok(test5,38,&Control,&State,1,t51,FALSE,0);
@@ -194,8 +220,11 @@ static void test_ScriptItemize( void )
 
     State.uBidiLevel = 1;
     test_items_ok(test1,4,&Control,&State,1,t12,FALSE,0);
+    test_items_ok(test1b,4,&Control,&State,1,t1b2,FALSE,0);
     test_items_ok(test2,16,&Control,&State,4,t23,FALSE,0);
     test_items_ok(test2b,11,&Control,&State,4,t2b2,FALSE,0);
+    test_items_ok(test2c,11,&Control,&State,4,t2c3,FALSE,0);
+    test_items_ok(test2d,11,&Control,&State,4,t2d3,FALSE,0);
     test_items_ok(test3,41,&Control,&State,1,t32,FALSE,0);
     test_items_ok(test4,12,&Control,&State,4,t42,FALSE,0);
     test_items_ok(test5,38,&Control,&State,1,t51,FALSE,0);
@@ -208,8 +237,11 @@ static void test_ScriptItemize( void )
     State.uBidiLevel = 1;
     Control.fMergeNeutralItems = TRUE;
     test_items_ok(test1,4,&Control,&State,1,t12,FALSE,0);
+    test_items_ok(test1b,4,&Control,&State,1,t1b2,FALSE,0);
     test_items_ok(test2,16,&Control,&State,4,t23,FALSE,0);
     test_items_ok(test2b,11,&Control,&State,2,t2b3,FALSE,4);
+    test_items_ok(test2c,11,&Control,&State,2,t2c4,FALSE,4);
+    test_items_ok(test2d,11,&Control,&State,2,t2d4,FALSE,4);
     test_items_ok(test3,41,&Control,&State,1,t32,FALSE,0);
     test_items_ok(test4,12,&Control,&State,3,t43,FALSE,4);
     test_items_ok(test5,38,&Control,&State,1,t51,FALSE,0);
diff --git a/dlls/usp10/usp10.c b/dlls/usp10/usp10.c
index 64b9f1114b2..c9ad77c2576 100644
--- a/dlls/usp10/usp10.c
+++ b/dlls/usp10/usp10.c
@@ -638,9 +638,22 @@ HRESULT WINAPI ScriptItemize(const WCHAR *pwcInChars, int cInChars, int cMaxItem
         }
     }
 
+    while (pwcInChars[cnt] == Numeric_space && cnt < cInChars)
+        cnt++;
+
+    if (cnt == cInChars) /* All Spaces */
+    {
+        cnt = 0;
+        New_Script = get_char_script(pwcInChars[cnt]);
+    }
+
     pItems[index].iCharPos = 0;
     pItems[index].a = scriptInformation[get_char_script(pwcInChars[cnt])].a;
 
+    if (strength)
+        str = strength[cnt];
+
+    cnt = 0;
     if (levels)
     {
         pItems[index].a.fRTL = odd(levels[cnt]);
@@ -654,9 +667,6 @@ HRESULT WINAPI ScriptItemize(const WCHAR *pwcInChars, int cInChars, int cMaxItem
         pItems[index].a.fRTL = odd(baselevel);
     }
 
-    if (strength)
-        str = strength[0];
-
     TRACE("New_Level=%i New_Strength=%i New_Script=%d, eScript=%d index=%d cnt=%d iCharPos=%d\n",
           levels?levels[cnt]:-1, str, New_Script, pItems[index].a.eScript, index, cnt,
           pItems[index].iCharPos);
@@ -668,6 +678,13 @@ HRESULT WINAPI ScriptItemize(const WCHAR *pwcInChars, int cInChars, int cMaxItem
 
         if(pwcInChars[cnt] != Numeric_space)
             New_Script = get_char_script(pwcInChars[cnt]);
+        else if (levels)
+        {
+            int j = 1;
+            while (cnt + j < cInChars - 1 && pwcInChars[cnt+j] == Numeric_space)
+                j++;
+            New_Script = get_char_script(pwcInChars[cnt+j]);
+        }
 
         if ((levels && (levels[cnt] != pItems[index].a.s.uBidiLevel || (strength && (strength[cnt] != str)))) || New_Script != pItems[index].a.eScript || New_Script == Script_Control)
         {