diff --git a/src/utils.zig b/src/utils.zig
index 0575462..8d9bfd3 100644
--- a/src/utils.zig
+++ b/src/utils.zig
@@ -115,11 +115,11 @@ test "getLongestAsciiArtRowLen" {
     try std.testing.expectEqual(40, try getLongestAsciiArtRowLen(rows[0..]));
 }
 
-pub fn readFile(allocator: std.mem.Allocator, file: std.fs.File, size: usize) ![]const u8 {
+pub fn readFile(allocator: std.mem.Allocator, io: std.Io, file: std.Io.File, size: usize) ![]const u8 {
     var file_buf = try allocator.alloc(u8, size);
     defer allocator.free(file_buf);
 
-    const read = try file.read(file_buf);
+    const read = try file.readPositionalAll(io, file_buf, 0);
 
     const data = file_buf[0..read];