diff --git a/lib/std/Target.zig b/lib/std/Target.zig
index 64608181fc..410bcbd1e2 100644
--- a/lib/std/Target.zig
+++ b/lib/std/Target.zig
@@ -2302,7 +2302,8 @@ pub fn c_type_bit_size(target: Target, c_type: CType) u16 {
             .char => return 8,
             .short, .ushort => return 16,
             .int, .uint, .float => return 32,
-            .long, .ulong, .longlong, .ulonglong, .double => return 64,
+            .long, .ulong, .double => return 64,
+            .longlong, .ulonglong => return 128,
             // Note: The OpenCL specification does not guarantee a particular size for long double,
             // but clang uses 128 bits.
             .longdouble => return 128,