diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd46934d5..3e3178e4f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
 - core: add refresh of window title on buffer switch, when option weechat.look.window_title is set
 - core: consider all keys are safe in cursor context ([#2244](https://github.com/weechat/weechat/issues/2244))
 - core: fix integer overflow with decimal numbers in calculation of expression
+- core: fix integer overflow in base32 encoding/decoding
 - irc: display nick changes and quit messages when option irc.look.ignore_tag_messages is enabled ([#2241](https://github.com/weechat/weechat/issues/2241))
 - perl: fix build when multiplicity is not available ([#2243](https://github.com/weechat/weechat/issues/2243))
 
diff --git a/src/core/core-string.c b/src/core/core-string.c
index 060ee0a8a..4254370f6 100644
--- a/src/core/core-string.c
+++ b/src/core/core-string.c
@@ -3572,7 +3572,8 @@ int
 string_base32_encode (const char *from, int length, char *to)
 {
     unsigned char base32_table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
-    int count, value, next, bits_left, pad, index;
+    unsigned int value;
+    int count, next, bits_left, pad, index;
     int length_padding[8] = { 0, 0, 6, 0, 4, 3, 0, 2 };
 
     if (!from || !to)
@@ -3650,7 +3651,8 @@ int
 string_base32_decode (const char *from, char *to)
 {
     const char *ptr_from;
-    int value, bits_left, count;
+    int bits_left, count;
+    unsigned int value;
     unsigned char c;
 
     if (!from || !to)