diff --git a/CHANGELOG.md b/CHANGELOG.md
index 54b33b8..2941631 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+#### V0.7.0
+
+- Support reflecting 128-bit integer types.
+
 #### v0.6.1
 
 - Add STACKS container to avoid creating new types in this module from jlrs.
diff --git a/src/Reflect.jl b/src/Reflect.jl
index 5ecb2ee..2181d4b 100644
--- a/src/Reflect.jl
+++ b/src/Reflect.jl
@@ -474,10 +474,12 @@ function insertbuiltins!(layouts::IdDict{DataType,Layout})::Nothing
     layouts[UInt16] = BuiltinLayout("u16", [], false, false, false)
     layouts[UInt32] = BuiltinLayout("u32", [], false, false, false)
     layouts[UInt64] = BuiltinLayout("u64", [], false, false, false)
+    layouts[UInt128] = BuiltinLayout("u128", [], false, false, false)
     layouts[Int8] = BuiltinLayout("i8", [], false, false, false)
     layouts[Int16] = BuiltinLayout("i16", [], false, false, false)
     layouts[Int32] = BuiltinLayout("i32", [], false, false, false)
     layouts[Int64] = BuiltinLayout("i64", [], false, false, false)
+    layouts[Int128] = BuiltinLayout("i128", [], false, false, false)
 
     layouts[Float32] = BuiltinLayout("f32", [], false, false, false)
     layouts[Float64] = BuiltinLayout("f64", [], false, false, false)
diff --git a/test/SingleFieldBits.jl b/test/SingleFieldBits.jl
index d80f7b1..ee269fd 100644
--- a/test/SingleFieldBits.jl
+++ b/test/SingleFieldBits.jl
@@ -54,6 +54,14 @@ struct BitsTypeFloat64
     a::Float64
 end
 
+struct BitsTypeU128
+    a::UInt128
+end
+
+struct BitsTypeI128
+    a::Int128
+end
+
 @testset "Single-field bits types" begin
     @test begin
         b = Reflect.reflect([BitsTypeBool])
@@ -222,4 +230,28 @@ end
             pub a: f64,
         }"""
     end
+
+    @test begin
+        b = Reflect.reflect([BitsTypeU128])
+        sb = Reflect.StringLayouts(b)
+
+        sb[BitsTypeU128] === """#[repr(C)]
+        #[derive(Clone, Debug, Unbox, ValidLayout, Typecheck, IntoJulia, ValidField, IsBits, ConstructType, CCallArg, CCallReturn)]
+        #[jlrs(julia_type = "Main.BitsTypeU128")]
+        pub struct BitsTypeU128 {
+            pub a: u128,
+        }"""
+    end
+
+    @test begin
+        b = Reflect.reflect([BitsTypeI128])
+        sb = Reflect.StringLayouts(b)
+
+        sb[BitsTypeI128] === """#[repr(C)]
+        #[derive(Clone, Debug, Unbox, ValidLayout, Typecheck, IntoJulia, ValidField, IsBits, ConstructType, CCallArg, CCallReturn)]
+        #[jlrs(julia_type = "Main.BitsTypeI128")]
+        pub struct BitsTypeI128 {
+            pub a: i128,
+        }"""
+    end
 end