diff --git a/spec/amber/helper_spec.cr b/spec/amber/helper_spec.cr
index a417de4..5828815 100644
--- a/spec/amber/helper_spec.cr
+++ b/spec/amber/helper_spec.cr
@@ -199,6 +199,7 @@ describe OpenAPI::Generator::Helpers::Amber do
           - union_types
           - free_form
           - array_of_hash
+          - tuple
           type: object
           properties:
             union_types:
@@ -219,6 +220,23 @@ describe OpenAPI::Generator::Helpers::Amber do
                   oneOf:
                   - type: integer
                   - type: string
+            tuple:
+              maxItems: 3
+              minItems: 3
+              type: array
+              items:
+                oneOf:
+                - type: integer
+                - type: string
+                - maxItems: 1
+                  minItems: 1
+                  type: array
+                  items:
+                    oneOf:
+                    - type: array
+                      items:
+                        type: number
+                    - type: boolean
         AmberSpec_Payload:
           required:
           - hello
diff --git a/spec/core/generator_spec.cr b/spec/core/generator_spec.cr
index da1150d..fd4a3aa 100644
--- a/spec/core/generator_spec.cr
+++ b/spec/core/generator_spec.cr
@@ -154,6 +154,7 @@ describe OpenAPI::Generator do
           - union_types
           - free_form
           - array_of_hash
+          - tuple
           type: object
           properties:
             union_types:
@@ -174,6 +175,23 @@ describe OpenAPI::Generator do
                   oneOf:
                   - type: integer
                   - type: string
+            tuple:
+              maxItems: 3
+              minItems: 3
+              type: array
+              items:
+                oneOf:
+                - type: integer
+                - type: string
+                - maxItems: 1
+                  minItems: 1
+                  type: array
+                  items:
+                    oneOf:
+                    - type: array
+                      items:
+                        type: number
+                    - type: boolean
       responses: {}
       parameters: {}
       examples: {}
diff --git a/spec/lucky/helper_spec.cr b/spec/lucky/helper_spec.cr
index 46ede90..2945334 100644
--- a/spec/lucky/helper_spec.cr
+++ b/spec/lucky/helper_spec.cr
@@ -150,6 +150,7 @@ describe OpenAPI::Generator::Helpers::Lucky do
           - union_types
           - free_form
           - array_of_hash
+          - tuple
           type: object
           properties:
             union_types:
@@ -170,6 +171,23 @@ describe OpenAPI::Generator::Helpers::Lucky do
                   oneOf:
                   - type: integer
                   - type: string
+            tuple:
+              maxItems: 3
+              minItems: 3
+              type: array
+              items:
+                oneOf:
+                - type: integer
+                - type: string
+                - maxItems: 1
+                  minItems: 1
+                  type: array
+                  items:
+                    oneOf:
+                    - type: array
+                      items:
+                        type: number
+                    - type: boolean
         LuckySpec_Payload:
           required:
           - hello
diff --git a/spec/spec_helper.cr b/spec/spec_helper.cr
index 2cda27f..d0c2d93 100644
--- a/spec/spec_helper.cr
+++ b/spec/spec_helper.cr
@@ -79,13 +79,15 @@ struct Model
     property union_types : Int32 | String | Hash(String, InnerModel)
     property free_form : JSON::Any
     property array_of_hash : Array(Hash(String, Int32 | String))
+    property tuple : Tuple(Int32, String, Tuple(Bool | Array(Float64)))
 
     SCHEMA = <<-JSON
     {
       "required": [
         "union_types",
         "free_form",
-        "array_of_hash"
+        "array_of_hash",
+        "tuple"
       ],
       "type": "object",
       "properties": {
@@ -124,6 +126,39 @@ struct Model
               ]
             }
           }
+        },
+        "tuple": {
+          "maxItems": 3,
+          "minItems": 3,
+          "type": "array",
+          "items": {
+            "oneOf": [
+              {
+                "type": "integer"
+              },
+              {
+                "type": "string"
+              },
+              {
+                "maxItems": 1,
+                "minItems": 1,
+                "type": "array",
+                "items": {
+                  "oneOf": [
+                    {
+                      "type": "array",
+                      "items": {
+                        "type": "number"
+                      }
+                    },
+                    {
+                      "type": "boolean"
+                    }
+                  ]
+                }
+              }
+            ]
+          }
         }
       }
     }
diff --git a/spec/spider-gazelle/helper_spec.cr b/spec/spider-gazelle/helper_spec.cr
index 2640c44..9f39872 100644
--- a/spec/spider-gazelle/helper_spec.cr
+++ b/spec/spider-gazelle/helper_spec.cr
@@ -206,6 +206,7 @@ describe OpenAPI::Generator::Helpers::ActionController do
           - union_types
           - free_form
           - array_of_hash
+          - tuple
           type: object
           properties:
             union_types:
@@ -226,6 +227,23 @@ describe OpenAPI::Generator::Helpers::ActionController do
                   oneOf:
                   - type: integer
                   - type: string
+            tuple:
+              maxItems: 3
+              minItems: 3
+              type: array
+              items:
+                oneOf:
+                - type: integer
+                - type: string
+                - maxItems: 1
+                  minItems: 1
+                  type: array
+                  items:
+                    oneOf:
+                    - type: array
+                      items:
+                        type: number
+                    - type: boolean
         ActionControllerSpec_Payload:
           required:
           - mandatory
diff --git a/src/openapi-generator/extensions.cr b/src/openapi-generator/extensions.cr
index d272fd1..e53cdf4 100644
--- a/src/openapi-generator/extensions.cr
+++ b/src/openapi-generator/extensions.cr
@@ -21,6 +21,38 @@ class Array(T)
   end
 end
 
+# :nodoc:
+# Define a `self.to_openapi_schema` method for the Tuple class.
+#
+# OpenAPI 3.0 does not support tuples (3.1 does), so we serialize it into a fixed bounds array.
+# see: https://github.com/OAI/OpenAPI-Specification/issues/1026
+struct Tuple
+  def self.to_openapi_schema
+    schema_items = uninitialized OpenAPI::Schema | OpenAPI::Reference
+
+    {% begin %}
+      {% types = [] of Types %}
+      {% for i in 0...T.size %}
+        {% for t in T[i].union_types %}
+          {% types << t %}
+        {% end %}
+      {% end %}
+
+      ::OpenAPI::Generator::Serializable.generate_schema(
+        schema_items,
+        types: {{ types }},
+      )
+    {% end %}
+
+    OpenAPI::Schema.new(
+      type: "array",
+      items: schema_items,
+      min_items: {{ T.size }},
+      max_items: {{ T.size }}
+    )
+  end
+end
+
 # :nodoc:
 # Define a `self.to_openapi_schema` method for the Hash class.
 class Hash(K, V)