diff --git a/mysql-test/r/ctype_utf32.result b/mysql-test/r/ctype_utf32.result
index 1f316b7b68f..ae55f2c101e 100644
--- a/mysql-test/r/ctype_utf32.result
+++ b/mysql-test/r/ctype_utf32.result
@@ -1269,6 +1269,9 @@ CHAR_LENGTH(TRIM(BOTH 0x61 FROM _utf32 0x00000061))
 SELECT CHAR_LENGTH(TRIM(BOTH 0x00 FROM _utf32 0x00000061));
 CHAR_LENGTH(TRIM(BOTH 0x00 FROM _utf32 0x00000061))
 1
+select hex(lower(cast(0xffff0000 as char character set utf32))) as c;
+c
+FFFF0000
 #
 # End of 5.5 tests
 #
diff --git a/mysql-test/t/ctype_utf32.test b/mysql-test/t/ctype_utf32.test
index 1be8925873c..8cbb8e2e55e 100644
--- a/mysql-test/t/ctype_utf32.test
+++ b/mysql-test/t/ctype_utf32.test
@@ -876,6 +876,11 @@ SELECT CHAR_LENGTH(TRIM(BOTH 0x0001 FROM _utf32 0x00000061));
 SELECT CHAR_LENGTH(TRIM(BOTH 0x61 FROM _utf32 0x00000061));
 SELECT CHAR_LENGTH(TRIM(BOTH 0x00 FROM _utf32 0x00000061));
 
+#
+# potential signedness issue
+#
+select hex(lower(cast(0xffff0000 as char character set utf32))) as c;
+
 --echo #
 --echo # End of 5.5 tests
 --echo #
diff --git a/strings/ctype-ucs2.c b/strings/ctype-ucs2.c
index a79f5899ec5..ca6f53f3f8d 100644
--- a/strings/ctype-ucs2.c
+++ b/strings/ctype-ucs2.c
@@ -1,5 +1,5 @@
 /* Copyright (c) 2003, 2013, Oracle and/or its affiliates
-   Copyright (c) 2009, 2014, SkySQL Ab.
+   Copyright (c) 2009, 2016, MariaDB
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ -1098,7 +1098,7 @@ my_uni_utf16(CHARSET_INFO *cs __attribute__((unused)),
 static inline void
 my_tolower_utf16(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256 && uni_plane[page])
     *wc= uni_plane[page][*wc & 0xFF].tolower;
 }
@@ -1107,7 +1107,7 @@ my_tolower_utf16(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 static inline void
 my_toupper_utf16(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256 && uni_plane[page])
     *wc= uni_plane[page][*wc & 0xFF].toupper;
 }
@@ -1116,7 +1116,7 @@ my_toupper_utf16(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 static inline void
 my_tosort_utf16(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256)
   {
     if (uni_plane[page])
@@ -1727,7 +1727,7 @@ my_uni_utf32(CHARSET_INFO *cs __attribute__((unused)),
 static inline void
 my_tolower_utf32(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256 && uni_plane[page])
     *wc= uni_plane[page][*wc & 0xFF].tolower;
 }
@@ -1736,7 +1736,7 @@ my_tolower_utf32(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 static inline void
 my_toupper_utf32(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256 && uni_plane[page])
     *wc= uni_plane[page][*wc & 0xFF].toupper;
 }
@@ -1745,7 +1745,7 @@ my_toupper_utf32(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 static inline void
 my_tosort_utf32(MY_UNICASE_INFO *const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256)
   {
     if (uni_plane[page])
diff --git a/strings/ctype-utf8.c b/strings/ctype-utf8.c
index 2dd7f5e6b92..f2782657bea 100644
--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -1,5 +1,5 @@
 /* Copyright (c) 2000, 2013, Oracle and/or its affiliates.
-   Copyright (c) 2009, 2013, Monty Program Ab
+   Copyright (c) 2009, 2016, MariaDB
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ -1939,7 +1939,7 @@ MY_UNICASE_INFO *const my_unicase_turkish[256]=
 static inline void
 my_tosort_unicode(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256)
   {
     if (uni_plane[page])
@@ -5024,7 +5024,7 @@ my_wc_mb_utf8mb4_no_range(CHARSET_INFO *cs __attribute__((unused)),
 static inline void
 my_tolower_utf8mb4(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256 && uni_plane[page])
     *wc= uni_plane[page][*wc & 0xFF].tolower;
 }
@@ -5033,7 +5033,7 @@ my_tolower_utf8mb4(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 static inline void
 my_toupper_utf8mb4(MY_UNICASE_INFO * const* uni_plane, my_wc_t *wc)
 {
-  int page= *wc >> 8;
+  uint page= *wc >> 8;
   if (page < 256 && uni_plane[page])
     *wc= uni_plane[page][*wc & 0xFF].toupper;
 }