diff --git a/src/string_immutable.zig b/src/string_immutable.zig
index c9437b757e..bbdea59cfc 100644
--- a/src/string_immutable.zig
+++ b/src/string_immutable.zig
@@ -385,7 +385,7 @@ inline fn eqlComptimeCheckLen(self: string, comptime alt: anytype, comptime chec
         },
         16 => {
             const first = comptime std.mem.readIntNative(u64, alt[0..8]);
-            const second = comptime std.mem.readIntNative(u64, alt[8..15]);
+            const second = comptime std.mem.readIntNative(u64, alt[8..16]);
             return ((comptime !check_len) or self.len == alt.len) and first == std.mem.readIntNative(u64, self[0..8]) and second == std.mem.readIntNative(u64, self[8..16]);
         },
         23 => {