diff --git a/Cargo.lock b/Cargo.lock
index 00afd2e..5dfd04c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -231,14 +231,14 @@ dependencies = [
 
 [[package]]
 name = "nutype"
-version = "0.4.1"
+version = "0.4.2"
 dependencies = [
  "nutype_macros",
 ]
 
 [[package]]
 name = "nutype_macros"
-version = "0.4.1"
+version = "0.4.2"
 dependencies = [
  "cfg-if",
  "kinded",
diff --git a/examples/no_std_example/Cargo.lock b/examples/no_std_example/Cargo.lock
index c7d4dd6..88119f1 100644
--- a/examples/no_std_example/Cargo.lock
+++ b/examples/no_std_example/Cargo.lock
@@ -47,14 +47,14 @@ dependencies = [
 
 [[package]]
 name = "nutype"
-version = "0.4.1"
+version = "0.4.2"
 dependencies = [
  "nutype_macros",
 ]
 
 [[package]]
 name = "nutype_macros"
-version = "0.4.1"
+version = "0.4.2"
 dependencies = [
  "cfg-if",
  "kinded",
diff --git a/nutype_macros/src/float/models.rs b/nutype_macros/src/float/models.rs
index 28bc074..bdc4fac 100644
--- a/nutype_macros/src/float/models.rs
+++ b/nutype_macros/src/float/models.rs
@@ -75,9 +75,7 @@ impl TypeTrait for FloatDeriveTrait {
 pub type FloatRawGuard<T> = RawGuard<SpannedFloatSanitizer<T>, SpannedFloatValidator<T>>;
 pub type FloatGuard<T> = Guard<FloatSanitizer<T>, FloatValidator<T>>;
 
-pub trait FloatType {
-    fn float_inner_type() -> FloatInnerType;
-}
+pub trait FloatType {}
 
 macro_rules! define_float_inner_type {
     ($($tp:ty => $variant:ident),*) => {
@@ -88,9 +86,6 @@ macro_rules! define_float_inner_type {
 
         $(
             impl FloatType for $tp {
-                fn float_inner_type() -> FloatInnerType {
-                    FloatInnerType::$variant
-                }
             }
         )*
 
diff --git a/nutype_macros/src/integer/models.rs b/nutype_macros/src/integer/models.rs
index 5505c8b..9fb3cd3 100644
--- a/nutype_macros/src/integer/models.rs
+++ b/nutype_macros/src/integer/models.rs
@@ -75,9 +75,7 @@ impl TypeTrait for IntegerDeriveTrait {
 pub type IntegerRawGuard<T> = RawGuard<SpannedIntegerSanitizer<T>, SpannedIntegerValidator<T>>;
 pub type IntegerGuard<T> = Guard<IntegerSanitizer<T>, IntegerValidator<T>>;
 
-pub trait IntegerType {
-    fn integer_inner_type() -> IntegerInnerType;
-}
+pub trait IntegerType {}
 
 macro_rules! define_integer_inner_type {
     ($($tp:ty => $variant:ident),*) => {
@@ -88,9 +86,6 @@ macro_rules! define_integer_inner_type {
 
         $(
             impl IntegerType for $tp {
-                fn integer_inner_type() -> IntegerInnerType {
-                    IntegerInnerType::$variant
-                }
             }
         )*