diff --git a/source/blender/editors/interface/interface.c b/source/blender/editors/interface/interface.c
index 5a70dc85530..78021612195 100644
--- a/source/blender/editors/interface/interface.c
+++ b/source/blender/editors/interface/interface.c
@@ -2156,8 +2156,14 @@ void ui_but_string_get_ex(uiBut *but, char *str, const size_t maxlen, const int
 			str[0] = '\0';
 		}
 		else if (buf && buf != str) {
+			BLI_assert(maxlen <= buf_len + 1);
 			/* string was too long, we have to truncate */
-			memcpy(str, buf, MIN2(maxlen, (size_t)(buf_len + 1)));
+			if (ui_but_is_utf8(but)) {
+				BLI_strncpy_utf8(str, buf, maxlen);
+			}
+			else {
+				BLI_strncpy(str, buf, maxlen);
+			}
 			MEM_freeN((void *)buf);
 		}
 	}