diff --git a/dlls/riched20/paint.c b/dlls/riched20/paint.c
index 47e4af1cbbf..565d4670842 100644
--- a/dlls/riched20/paint.c
+++ b/dlls/riched20/paint.c
@@ -1230,18 +1230,19 @@ ME_SetZoom(ME_TextEditor *editor, int numerator, int denominator)
 {
   /* TODO: Zoom images and objects */
 
-  if (numerator != 0)
+  if (numerator == 0 && denominator == 0)
   {
-    if (denominator == 0)
-      return FALSE;
-    if (1.0 / 64.0 > (float)numerator / (float)denominator
-        || (float)numerator / (float)denominator > 64.0)
-      return FALSE;
+    editor->nZoomNumerator = editor->nZoomDenominator = 0;
+    return TRUE;
   }
-  
+  if (numerator <= 0 || denominator <= 0)
+    return FALSE;
+  if (numerator * 64 <= denominator || numerator / denominator >= 64)
+    return FALSE;
+
   editor->nZoomNumerator = numerator;
   editor->nZoomDenominator = denominator;
-  
+
   ME_RewrapRepaint(editor);
   return TRUE;
 }
diff --git a/dlls/riched20/tests/editor.c b/dlls/riched20/tests/editor.c
index 4165f5ef144..633620ba4ad 100644
--- a/dlls/riched20/tests/editor.c
+++ b/dlls/riched20/tests/editor.c
@@ -6376,27 +6376,27 @@ static void test_zoom(void)
     ok(ret == TRUE, "EM_SETZOOM rejected valid values (%d).\n", ret);
 
     ret = SendMessage(hwnd, EM_SETZOOM, (WPARAM)2, (LPARAM)128);
-    todo_wine ok(ret == FALSE, "EM_SETZOOM accepted invalid values (%d).\n", ret);
+    ok(ret == FALSE, "EM_SETZOOM accepted invalid values (%d).\n", ret);
 
     ret = SendMessage(hwnd, EM_GETZOOM, (WPARAM)&numerator, (LPARAM)&denominator);
-    todo_wine ok(numerator == 127, "incorrect numerator is %d\n", numerator);
-    todo_wine ok(denominator == 2, "incorrect denominator is %d\n", denominator);
+    ok(numerator == 127, "incorrect numerator is %d\n", numerator);
+    ok(denominator == 2, "incorrect denominator is %d\n", denominator);
     ok(ret == TRUE, "EM_GETZOOM failed (%d).\n", ret);
 
     ret = SendMessage(hwnd, EM_SETZOOM, (WPARAM)128, (LPARAM)2);
-    todo_wine ok(ret == FALSE, "EM_SETZOOM accepted invalid values (%d).\n", ret);
+    ok(ret == FALSE, "EM_SETZOOM accepted invalid values (%d).\n", ret);
 
     /* See if negative numbers are accepted. */
     ret = SendMessage(hwnd, EM_SETZOOM, (WPARAM)-100, (LPARAM)-100);
-    todo_wine ok(ret == FALSE, "EM_SETZOOM accepted invalid values (%d).\n", ret);
+    ok(ret == FALSE, "EM_SETZOOM accepted invalid values (%d).\n", ret);
 
     /* See if negative numbers are accepted. */
     ret = SendMessage(hwnd, EM_SETZOOM, (WPARAM)0, (LPARAM)100);
-    todo_wine ok(ret == FALSE, "EM_SETZOOM failed (%d).\n", ret);
+    ok(ret == FALSE, "EM_SETZOOM failed (%d).\n", ret);
 
     ret = SendMessage(hwnd, EM_GETZOOM, (WPARAM)&numerator, (LPARAM)&denominator);
-    todo_wine ok(numerator == 127, "incorrect numerator is %d\n", numerator);
-    todo_wine ok(denominator == 2, "incorrect denominator is %d\n", denominator);
+    ok(numerator == 127, "incorrect numerator is %d\n", numerator);
+    ok(denominator == 2, "incorrect denominator is %d\n", denominator);
     ok(ret == TRUE, "EM_GETZOOM failed (%d).\n", ret);
 
     /* Reset the zoom value */