diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9fc04ab88..416b64ac2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
 - api: fix infinite loop in function string_replace when the search string is empty
 - irc: fix tag in message with list of names when joining a channel
 - fset: remove error displayed in core buffer when clicking with the mouse below the last option displayed
+- guile: fix conversion of dates in the API functions
 - irc: limit size of data received from the server to prevent memory exhaustion
 - irc: fix out-of-bounds read on incoming DCC command with a quoted filename ending the message ([#2322](https://github.com/weechat/weechat/issues/2322))
 - relay: limit size of decompressed websocket frame with permessage-deflate to prevent memory exhaustion ([GHSA-v2v4-45wm-5cr3](https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3), [CVE-2026-53524](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-53524))
diff --git a/src/plugins/guile/weechat-guile-api.c b/src/plugins/guile/weechat-guile-api.c
index 78423a12e..5b215d186 100644
--- a/src/plugins/guile/weechat-guile-api.c
+++ b/src/plugins/guile/weechat-guile-api.c
@@ -2096,7 +2096,7 @@ weechat_guile_api_print_date_tags (SCM buffer, SCM date, SCM tags, SCM message)
     plugin_script_api_printf_date_tags (weechat_guile_plugin,
                                         guile_current_script,
                                         API_STR2PTR(API_SCM_TO_STRING(buffer)),
-                                        (time_t)scm_to_long (date),
+                                        (time_t)scm_to_long_long (date),
                                         API_SCM_TO_STRING(tags),
                                         "%s", API_SCM_TO_STRING(message));
 
@@ -2117,7 +2117,7 @@ weechat_guile_api_print_datetime_tags (SCM buffer, SCM date, SCM date_usec,
         weechat_guile_plugin,
         guile_current_script,
         API_STR2PTR(API_SCM_TO_STRING(buffer)),
-        (time_t)scm_to_long (date),
+        (time_t)scm_to_long_long (date),
         scm_to_int (date_usec),
         API_SCM_TO_STRING(tags),
         "%s", API_SCM_TO_STRING(message));
@@ -2156,7 +2156,7 @@ weechat_guile_api_print_y_date_tags (SCM buffer, SCM y, SCM date, SCM tags,
                                           guile_current_script,
                                           API_STR2PTR(API_SCM_TO_STRING(buffer)),
                                           scm_to_int (y),
-                                          (time_t)scm_to_long (date),
+                                          (time_t)scm_to_long_long (date),
                                           API_SCM_TO_STRING(tags),
                                           "%s", API_SCM_TO_STRING(message));
 
@@ -2178,7 +2178,7 @@ weechat_guile_api_print_y_datetime_tags (SCM buffer, SCM y, SCM date,
         guile_current_script,
         API_STR2PTR(API_SCM_TO_STRING(buffer)),
         scm_to_int (y),
-        (time_t)scm_to_long (date),
+        (time_t)scm_to_long_long (date),
         scm_to_int (date_usec),
         API_SCM_TO_STRING(tags),
         "%s", API_SCM_TO_STRING(message));
@@ -4748,7 +4748,7 @@ weechat_guile_api_infolist_new_var_time (SCM item, SCM name, SCM value)
 
     result = API_PTR2STR(weechat_infolist_new_var_time (API_STR2PTR(API_SCM_TO_STRING(item)),
                                                         API_SCM_TO_STRING(name),
-                                                        (time_t)scm_to_long (value)));
+                                                        (time_t)scm_to_long_long (value)));
 
     API_RETURN_STRING(result);
 }