diff --git a/build/Makefile b/build/Makefile
index 33a4752..672f711 100644
--- a/build/Makefile
+++ b/build/Makefile
@@ -6,7 +6,7 @@ CFG_DIR = $(BASE_DIR)/cfg
 LIBS = libtoxcore ncursesw libconfig
 
 CFLAGS = -std=gnu99 -pthread -Wall -g
-CFLAGS += '-DTOXICVER="$(VERSION)"' -DHAVE_WIDECHAR -D_XOPEN_SOURCE_EXTENDED
+CFLAGS += '-DTOXICVER="$(VERSION)"' -DHAVE_WIDECHAR -D_XOPEN_SOURCE_EXTENDED -D_FILE_OFFSET_BITS=64
 CFLAGS += '-DPACKAGE_DATADIR="$(abspath $(DATADIR))"'
 CFLAGS += $(USER_CFLAGS)
 LDFLAGS = $(USER_LDFLAGS)
diff --git a/src/chat_commands.c b/src/chat_commands.c
index 00d576f..62d8b62 100644
--- a/src/chat_commands.c
+++ b/src/chat_commands.c
@@ -224,7 +224,7 @@ void cmd_sendfile(WINDOW *window, ToxWindow *self, Tox *m, int argc, char (*argv
         return;
     }
 
-    uint64_t filesize = file_size(path);
+    off_t filesize = file_size(path);
 
     if (filesize == -1) {
         line_info_add(self, NULL, NULL, NULL, SYS_MSG, 0, 0, "File corrupt.");
diff --git a/src/friendlist.c b/src/friendlist.c
index 67fcd85..0f0c88e 100644
--- a/src/friendlist.c
+++ b/src/friendlist.c
@@ -181,7 +181,7 @@ int load_blocklist(char *path)
     if (fp == NULL)
         return -1;
 
-    uint64_t len = file_size(path);
+    off_t len = file_size(path);
 
     if (len == -1) {
         fclose(fp);
diff --git a/src/log.c b/src/log.c
index d727870..b73b2df 100644
--- a/src/log.c
+++ b/src/log.c
@@ -156,9 +156,9 @@ void load_chat_history(ToxWindow *self, struct chatlog *log)
     if (log->file == NULL)
         return;
 
-    uint64_t sz = file_size(log->path);
+    off_t sz = file_size(log->path);
 
-    if (sz <= 0)
+    if (sz == 0)
         return;
 
     char *hstbuf = malloc(sz);
diff --git a/src/misc_tools.c b/src/misc_tools.c
index 8b928c4..c7ecf0e 100644
--- a/src/misc_tools.c
+++ b/src/misc_tools.c
@@ -313,12 +313,12 @@ bool file_exists(const char *path)
 }
 
 /* returns file size or -1 on error */
-uint64_t file_size(const char *path)
+off_t file_size(const char *path)
 {
     struct stat st;
 
     if (stat(path, &st) == -1)
         return -1;
 
-    return (uint64_t) st.st_size;
+    return st.st_size;
 }
diff --git a/src/misc_tools.h b/src/misc_tools.h
index e6f66a2..472fdfe 100644
--- a/src/misc_tools.h
+++ b/src/misc_tools.h
@@ -113,6 +113,6 @@ void bytes_convert_str(char *buf, int size, uint64_t bytes);
 bool file_exists(const char *path);
 
 /* returns file size or -1 on error */
-uint64_t file_size(const char *path);
+off_t file_size(const char *path);
 
 #endif /* #define MISC_TOOLS_H */
diff --git a/src/toxic.c b/src/toxic.c
index bc20bea..126fef3 100644
--- a/src/toxic.c
+++ b/src/toxic.c
@@ -629,7 +629,7 @@ static void load_data(Tox *m, char *path)
     FILE *fd;
 
     if ((fd = fopen(path, "rb")) != NULL) {
-        uint64_t len = file_size(path);
+        off_t len = file_size(path);
 
         if (len == -1) {
             fclose(fd);