diff --git a/ChangeLog b/ChangeLog
index b3e374c244..a878b775ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri May  6 02:28:31 2016  Masaki Suketa <masaki.suketa@nifty.ne.jp>
+
+	* ext/win32ole/win32ole.c (ole_vstr2wc, ole_variant2val): fix blank
+	  string conversion.
+	  [Bug #11880]
+	  Thanks Akio Tajima for the patch!
+
 Fri May  6 02:24:13 2016  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* bignum.c: [DOC] Update result of 123456789 ** -2.
diff --git a/ext/win32ole/win32ole.c b/ext/win32ole/win32ole.c
index 02ad82b4d4..ac3c2a6a73 100644
--- a/ext/win32ole/win32ole.c
+++ b/ext/win32ole/win32ole.c
@@ -864,6 +864,9 @@ ole_vstr2wc(VALUE vstr)
     /* do not type-conversion here to prevent from other arguments
      * changing (if exist) */
     Check_Type(vstr, T_STRING);
+    if (RSTRING_LEN(vstr) == 0) {
+        return NULL;
+    }
 
     enc = rb_enc_get(vstr);
 
@@ -1571,10 +1574,16 @@ ole_variant2val(VARIANT *pvar)
 
     case VT_BSTR:
     {
-        if(V_ISBYREF(pvar))
-            obj = ole_wc2vstr(*V_BSTRREF(pvar), FALSE);
-        else
-            obj = ole_wc2vstr(V_BSTR(pvar), FALSE);
+        if(V_ISBYREF(pvar)) {
+            obj = (SysStringLen(*V_BSTRREF(pvar)) == 0)
+                ? rb_str_new2("")
+                : ole_wc2vstr(*V_BSTRREF(pvar), FALSE);
+        }
+        else {
+            obj = (SysStringLen(V_BSTR(pvar)) == 0)
+                ? rb_str_new2("")
+                : ole_wc2vstr(V_BSTR(pvar), FALSE);
+        }
         break;
     }
 
diff --git a/version.h b/version.h
index 8a4b0efe18..723c3eb39a 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.2"
 #define RUBY_RELEASE_DATE "2016-05-06"
-#define RUBY_PATCHLEVEL 116
+#define RUBY_PATCHLEVEL 117
 
 #define RUBY_RELEASE_YEAR 2016
 #define RUBY_RELEASE_MONTH 5