diff --git a/json_typegen_shared/src/generation/json_schema.rs b/json_typegen_shared/src/generation/json_schema.rs
index 274efa3..dc4bc10 100644
--- a/json_typegen_shared/src/generation/json_schema.rs
+++ b/json_typegen_shared/src/generation/json_schema.rs
@@ -53,6 +53,7 @@ fn type_from_shape(ctxt: &mut Ctxt, path: &str, shape: &Shape) -> Value {
         MapT { val_type: v } => generate_map_type(ctxt, path, v),
         Opaque(t) => Value::Object(string_hashmap! { "type" => Value::String(t.clone()) }),
         Optional(e) => type_from_shape(ctxt, path, e),
+        Nullable(e) => type_from_shape(ctxt, path, e),
     }
 }
 
diff --git a/json_typegen_shared/src/generation/kotlin.rs b/json_typegen_shared/src/generation/kotlin.rs
index 54a8a26..d87b022 100644
--- a/json_typegen_shared/src/generation/kotlin.rs
+++ b/json_typegen_shared/src/generation/kotlin.rs
@@ -80,6 +80,14 @@ fn type_from_shape(ctxt: &mut Ctxt, path: &str, shape: &Shape) -> (Ident, Option
             } else {
                 (format!("{}?", inner), defs)
             }
+        },
+        Nullable(e) => {
+            let (inner, defs) = type_from_shape(ctxt, path, e);
+            if ctxt.options.use_default_for_missing_fields {
+                (inner, defs)
+            } else {
+                (format!("{}?", inner), defs)
+            }
         }
     }
 }
diff --git a/json_typegen_shared/src/generation/python.rs b/json_typegen_shared/src/generation/python.rs
index 675b16c..a9fe78b 100644
--- a/json_typegen_shared/src/generation/python.rs
+++ b/json_typegen_shared/src/generation/python.rs
@@ -126,6 +126,15 @@ fn type_from_shape(ctxt: &mut Ctxt, path: &str, shape: &Shape) -> (Ident, Option
                 let optional = import(ctxt, Import::Optional);
                 (format!("{}[{}]", optional, inner), defs)
             }
+        },
+        Nullable(e) => {
+            let (inner, defs) = type_from_shape(ctxt, path, e);
+            if ctxt.options.use_default_for_missing_fields {
+                (inner, defs)
+            } else {
+                let optional = import(ctxt, Import::Optional);
+                (format!("{}[{}]", optional, inner), defs)
+            }
         }
     }
 }
diff --git a/json_typegen_shared/src/generation/rust.rs b/json_typegen_shared/src/generation/rust.rs
index cf274aa..3715384 100644
--- a/json_typegen_shared/src/generation/rust.rs
+++ b/json_typegen_shared/src/generation/rust.rs
@@ -94,7 +94,15 @@ fn type_from_shape(ctxt: &mut Ctxt, path: &str, shape: &Shape) -> (Ident, Option
             } else {
                 (format!("Option<{}>", inner), defs)
             }
-        }
+        },
+        Nullable(e) => {
+            let (inner, defs) = type_from_shape(ctxt, path, e);
+            if ctxt.options.use_default_for_missing_fields {
+                (inner, defs)
+            } else {
+                (format!("Option<{}>", inner), defs)
+            }
+        },
     }
 }
 
diff --git a/json_typegen_shared/src/generation/shape.rs b/json_typegen_shared/src/generation/shape.rs
index 08037b3..f090f67 100644
--- a/json_typegen_shared/src/generation/shape.rs
+++ b/json_typegen_shared/src/generation/shape.rs
@@ -46,6 +46,10 @@ fn type_from_shape(ctxt: &mut Ctxt, shape: &Shape) -> Value {
             "__type__" => Value::Str("optional"),
             "item" => type_from_shape(ctxt, e),
         }),
+        Nullable(e) => Value::Object(string_hashmap! {
+            "__type__" => Value::Str("nullable"),
+            "item" => type_from_shape(ctxt, e),
+        }),
     }
 }
 
diff --git a/json_typegen_shared/src/generation/typescript.rs b/json_typegen_shared/src/generation/typescript.rs
index b10ec3c..cfbc84f 100644
--- a/json_typegen_shared/src/generation/typescript.rs
+++ b/json_typegen_shared/src/generation/typescript.rs
@@ -64,6 +64,10 @@ fn type_from_shape(ctxt: &mut Ctxt, path: &str, shape: &Shape) -> (Ident, Option
             } else {
                 (format!("{} | undefined", inner), defs)
             }
+        },
+        Nullable(e) => {
+            let (inner, defs) = type_from_shape(ctxt, path, e);
+            (format!("{} | null", inner), defs)
         }
     }
 }
diff --git a/json_typegen_shared/src/generation/typescript_type_alias.rs b/json_typegen_shared/src/generation/typescript_type_alias.rs
index c4fa488..b0f184c 100644
--- a/json_typegen_shared/src/generation/typescript_type_alias.rs
+++ b/json_typegen_shared/src/generation/typescript_type_alias.rs
@@ -49,7 +49,15 @@ fn type_from_shape(ctxt: &mut Ctxt, shape: &Shape) -> Code {
             } else {
                 format!("{} | undefined", inner)
             }
-        }
+        },
+        Nullable(e) => {
+            let inner = type_from_shape(ctxt, e);
+            if ctxt.options.use_default_for_missing_fields {
+                inner
+            } else {
+                format!("{} | null", inner)
+            }
+        },
     }
 }
 
diff --git a/json_typegen_shared/src/shape.rs b/json_typegen_shared/src/shape.rs
index 08ad9ff..d804798 100644
--- a/json_typegen_shared/src/shape.rs
+++ b/json_typegen_shared/src/shape.rs
@@ -15,9 +15,10 @@ pub enum Shape {
     /// represented by any single shape
     Any,
 
-    /// `Optional(T)` represents that a value is nullable, or not always present
+    /// `Optional(T)` represents that a value is not always present
     Optional(Box<Shape>),
-
+    /// `Nullable(T)` represents that a value is nullable
+    Nullable(Box<Shape>),
     /// Equivalent to `Optional(Bottom)`, `Null` represents optionality with no further information
     Null,
 
@@ -50,7 +51,7 @@ pub fn common_shape(a: Shape, b: Shape) -> Shape {
     match (a, b) {
         (a, Bottom) | (Bottom, a) => a,
         (Integer, Floating) | (Floating, Integer) => Floating,
-        (a, Null) | (Null, a) => a.into_optional(),
+        (a, Null) | (Null, a) => a.into_nullable(),
         (a, Optional(b)) | (Optional(b), a) => common_shape(a, *b).into_optional(),
         (Tuple(shapes1, n1), Tuple(shapes2, n2)) => {
             if shapes1.len() == shapes2.len() {
@@ -81,6 +82,7 @@ pub fn common_shape(a: Shape, b: Shape) -> Shape {
             fields: common_field_shapes(f1, f2),
         },
         (Opaque(t), _) | (_, Opaque(t)) => Opaque(t),
+        (a, Nullable(b)) | (Nullable(b), a) => common_shape(a, *b).into_nullable(),
         _ => Any,
     }
 }
@@ -113,10 +115,19 @@ impl Shape {
     fn into_optional(self) -> Self {
         use self::Shape::*;
         match self {
-            Null | Any | Bottom | Optional(_) => self,
+            Null => Nullable(Box::new(self)),
+            Any | Bottom | Optional(_) => self,
             non_nullable => Optional(Box::new(non_nullable)),
         }
     }
+    fn into_nullable(self) -> Self {
+        use self::Shape::*;
+        match self {
+            Null => Nullable(Box::new(self)),
+            Any | Bottom | Nullable(_) => self,
+            non_nullable => Nullable(Box::new(non_nullable)),
+        }
+    }
 
     /// Note: This is asymmetrical because we don't unify based on this,
     /// but check if `self` can be used *as is* as a replacement for `other`