diff --git a/mod.ts b/mod.ts
index c15ab4e0..f7a2ec98 100644
--- a/mod.ts
+++ b/mod.ts
@@ -1,80 +1,7 @@
 import { asserts } from "./deps.ts";
 import { MockServerRequest } from "./src/mocks/server_request.ts";
 import { TestCase } from "./src/test_case.ts";
-
-/**
- * Example:
- *
- * {
- *   suites: {
- *     "My Suite": {
- *       cases: [
- *         {
- *           name: "My Case",
- *           new_name: this.formatTestCaseName(name),
- *           testFn: Function
- *         },
- *         ...
- *       ],
- *       after_all_case_hook: Function,
- *       after_each_case_hook: Function,
- *       before_all_case_hook: Function,
- *       before_each_case_hook: Function
- *     },
- *     ... // More suites allowed
- *   },
- *   after_all_suite_hook: Function;
- *   after_each_suite_hook: Function;
- *   before_all_suite_hook: Function;
- *   before_each_suite_hook: Function;
- * }
- *
- * or:
- *
- * {
-     suites: {
-       run(): {
-         cases: [Array],
-         after_all_case_hook: [Function],
-         before_all_case_hook: [Function],
-         before_each_case_hook: [Function],
-         after_each_case_hook: [Function]
-       },
-       close(): {
-         cases: [Array],
-         after_all_case_hook: [Function],
-         before_all_case_hook: [Function],
-         before_each_case_hook: [Function],
-         after_each_case_hook: [Function]
-       }
-     },
-      before_each_suite_hook: [Function],
-      after_each_suite_hook: [Function],
-     after_all_suite_hook: [Function],
-     before_all_suite_hook: [Function]
- * }
- */
-interface Plan {
-  [key: string]: { // Plan name
-    suites?: {
-      [key: string]: { // suite names
-        cases?: Array<{
-          name: string;
-          new_name: string;
-          testFn: Function;
-        }>;
-        after_all_case_hook?: Function;
-        after_each_case_hook?: Function;
-        before_all_case_hook?: Function;
-        before_each_case_hook?: Function;
-      };
-    };
-    after_all_suite_hook?: Function;
-    after_each_suite_hook?: Function;
-    before_all_suite_hook?: Function;
-    before_each_suite_hook?: Function;
-  };
-}
+import { ITestPlan, ITestSuite, ITestCase } from "./src/interfaces.ts";
 
 /**
  * @description
@@ -131,7 +58,7 @@ export class RhumRunner {
   protected passed_in_test_suite: string = "";
   protected test_plan_in_progress: string = "";
   protected test_suite_in_progress: string = "";
-  protected plan: any = {}; // TODO(ebebbington) Needs a type, use Plan interface but fix the TS errors it gives
+  protected plan: ITestPlan = { suites: {} };
 
   // FILE MARKER - METHODS - CONSTRUCTOR ///////////////////////////////////////
 
@@ -159,7 +86,7 @@ export class RhumRunner {
     // Check if the hook is for test cases inside of a suite
     if (this.passed_in_test_plan && this.passed_in_test_suite) {
       // is a before each inside a suite for every test case
-      this.plan.suites[this.passed_in_test_suite].before_each_case_hook = cb;
+      this.plan.suites![this.passed_in_test_suite].before_each_case_hook = cb;
     } else if (this.passed_in_test_plan && !this.passed_in_test_suite) {
       // before each hooks for the suites
       this.plan.before_each_suite_hook = cb;
@@ -180,7 +107,7 @@ export class RhumRunner {
     // Check if the hook is for test cases inside of a suite
     if (this.passed_in_test_plan && this.passed_in_test_suite) {
       // is a after each inside a suite for every test case
-      this.plan.suites[this.passed_in_test_suite].after_each_case_hook = cb;
+      this.plan.suites![this.passed_in_test_suite].after_each_case_hook = cb;
     } else if (this.passed_in_test_plan && !this.passed_in_test_suite) {
       // after each hooks for the suites
       this.plan.after_each_suite_hook = cb;
@@ -201,7 +128,7 @@ export class RhumRunner {
     // Check if the hook is for test cases inside of a suite
     if (this.passed_in_test_plan && this.passed_in_test_suite) {
       // is a before all inside a suite for every test case
-      this.plan.suites[this.passed_in_test_suite].after_all_case_hook = cb;
+      this.plan.suites![this.passed_in_test_suite].after_all_case_hook = cb;
     } else if (this.passed_in_test_plan && !this.passed_in_test_suite) {
       // before all hooks for the suites
       this.plan.after_all_suite_hook = cb;
@@ -222,7 +149,7 @@ export class RhumRunner {
     // Check if the hook is for test cases inside of a suite
     if (this.passed_in_test_plan && this.passed_in_test_suite) {
       // is a before all inside a suite for every test case
-      this.plan.suites[this.passed_in_test_suite].before_all_case_hook = cb;
+      this.plan.suites![this.passed_in_test_suite].before_all_case_hook = cb;
     } else if (this.passed_in_test_plan && !this.passed_in_test_suite) {
       // before all hooks for the suites
       this.plan.before_all_suite_hook = cb;
@@ -268,7 +195,7 @@ export class RhumRunner {
    * @return void
    */
   public testCase(name: string, testFn: Function): void {
-    this.plan.suites[this.passed_in_test_suite].cases.push({
+    this.plan.suites[this.passed_in_test_suite].cases!.push({
       name,
       new_name: this.formatTestCaseName(name),
       testFn,
@@ -289,9 +216,6 @@ export class RhumRunner {
   public testPlan(name: string, testSuites: Function): void {
     this.passed_in_test_suite = ""; // New plan
     this.passed_in_test_plan = name;
-    this.plan = {
-      suites: {},
-    };
     testSuites();
   }
 
@@ -308,7 +232,7 @@ export class RhumRunner {
    */
   public testSuite(name: string, testCases: Function): void {
     this.passed_in_test_suite = name;
-    this.plan.suites[name] = { cases: [] };
+    this.plan.suites![name] = { cases: [] };
     testCases();
   }
 
diff --git a/src/interfaces.ts b/src/interfaces.ts
new file mode 100644
index 00000000..985b3c14
--- /dev/null
+++ b/src/interfaces.ts
@@ -0,0 +1,126 @@
+/**
+ * @description
+ *
+ *     suites
+ *         An object of objects matching the ITestSuite interface.
+ *
+ *     after_all_suite_hook?
+ *         A callback function to execute after all test suites.
+ *
+ *     after_each_suite_hook?
+ *         A callback function to execute after each test suite.
+ *
+ *     before_all_suite_hook?
+ *         A callback function to execute before all test suites.
+ *
+ *     before_each_suite_hook?
+ *         A callback function to execute before each test suite.
+ *
+ *
+ * Example below ...
+ *
+ *     {
+ *       suites: {
+ *         "My Suite": {
+ *           cases: [
+ *             {
+ *               name: "My Case",
+ *               new_name: this.formatTestCaseName(name),
+ *               testFn: Function
+ *             },
+ *             ...
+ *           ],
+ *           after_all_case_hook: Function,
+ *           after_each_case_hook: Function,
+ *           before_all_case_hook: Function,
+ *           before_each_case_hook: Function
+ *         },
+ *         ... // More suites allowed
+ *       },
+ *       after_all_suite_hook: Function;
+ *       after_each_suite_hook: Function;
+ *       before_all_suite_hook: Function;
+ *       before_each_suite_hook: Function;
+ *     }
+ *
+ * ... or ...
+ *
+ *     {
+ *       suites: {
+ *         run(): {
+ *           cases: [Array],
+ *           after_all_case_hook: [Function],
+ *           before_all_case_hook: [Function],
+ *           before_each_case_hook: [Function],
+ *           after_each_case_hook: [Function]
+ *         },
+ *         close(): {
+ *           cases: [Array],
+ *           after_all_case_hook: [Function],
+ *           before_all_case_hook: [Function],
+ *           before_each_case_hook: [Function],
+ *           after_each_case_hook: [Function]
+ *         }
+ *       },
+ *       before_each_suite_hook: [Function],
+ *       after_each_suite_hook: [Function],
+ *       after_all_suite_hook: [Function],
+ *       before_all_suite_hook: [Function]
+ *     }
+ */
+export interface ITestPlan {
+  suites: {
+    [key: string]: ITestSuite; // "key" is the suite name
+  };
+  after_all_suite_hook?: Function;
+  after_each_suite_hook?: Function;
+  before_all_suite_hook?: Function;
+  before_each_suite_hook?: Function;
+}
+
+/**
+ * @description
+ *     cases?
+ *         An array of objects matching the ITestCase interface.
+ *
+ *     after_all_case_hook?
+ *         A callback function to execute after all test cases.
+ *
+ *     after_each_case_hook?
+ *         A callback function to execute after each test case.
+ *
+ *     before_all_case_hook?
+ *         A callback function to execute before all test cases.
+ *
+ *     before_each_case_hook?
+ *         A callback function to execute before each test case.
+ */
+export interface ITestSuite {
+  cases?: ITestCase[];
+  after_all_case_hook?: Function;
+  after_each_case_hook?: Function;
+  before_all_case_hook?: Function;
+  before_each_case_hook?: Function;
+}
+
+/**
+ * @description
+ *     name
+ *         The name of the test case.
+ *
+ *     new_name
+ *         The new name of the test. This is strictly for outputting purposes.
+ *         Deno's test runner outputs "test name of test" and we want to
+ *         overwrite that text. This new_name string helps us do that. See
+ *         formatTestCaseName() in mod.ts for more information.
+ *
+ *     testFn
+ *         The test function. Ultimately, this gets passed as the second
+ *         argument of Deno.test().
+ */
+export interface ITestCase {
+  name: string;
+  new_name: string;
+  testFn: Function;
+}
+
diff --git a/src/test_case.ts b/src/test_case.ts
index 1b336c7b..3acf3e94 100644
--- a/src/test_case.ts
+++ b/src/test_case.ts
@@ -1,12 +1,13 @@
 const encoder = new TextEncoder();
+import { ITestPlan, ITestCase } from "./interfaces.ts";
 
 /**
  * A class to help create uniform test case objects.
  */
 export class TestCase {
-  protected plan: any; // TODO(ebebbington) Use Plan interface
+  protected plan: ITestPlan;
 
-  constructor(plan: any) { // TODO(ebebbington) Use Plan interface
+  constructor(plan: ITestPlan) {
     this.plan = plan;
   }
 
@@ -16,7 +17,7 @@ export class TestCase {
     }
     Object.keys(this.plan.suites).forEach((suiteName) => {
       // Run cases
-      this.plan.suites[suiteName].cases.forEach(async (c: any) => {
+      this.plan!.suites[suiteName].cases!.forEach(async (c: ITestCase) => {
         // Run the case - required to run like this because the
         // hooks need to be ran inside the Deno.test call. Deno.test seems to queue
         // the tests, meaning all hooks are ran, and **then** the tests are ran
@@ -28,17 +29,17 @@ export class TestCase {
             this.plan.before_each_suite_hook();
           }
           if (this.plan.suites[suiteName].before_all_case_hook) {
-            this.plan.suites[suiteName].before_all_case_hook();
+            this.plan.suites[suiteName].before_all_case_hook!();
           }
           if (this.plan.suites[suiteName].before_each_case_hook) {
-            this.plan.suites[suiteName].before_each_case_hook();
+            this.plan.suites[suiteName].before_each_case_hook!();
           }
           await c.testFn();
           if (this.plan.suites[suiteName].after_each_case_hook) {
-            this.plan.suites[suiteName].after_each_case_hook();
+            this.plan.suites[suiteName].after_each_case_hook!();
           }
           if (this.plan.suites[suiteName].after_all_case_hook) {
-            this.plan.suites[suiteName].after_all_case_hook();
+            this.plan.suites[suiteName].after_all_case_hook!();
           }
           if (this.plan.after_each_suite_hook) {
             this.plan.after_each_suite_hook();
diff --git a/tests/integration/hooks/after_all_test.ts b/tests/integration/hooks/after_all_test.ts
index 99820225..d0852717 100644
--- a/tests/integration/hooks/after_all_test.ts
+++ b/tests/integration/hooks/after_all_test.ts
@@ -26,8 +26,8 @@ Rhum.testPlan("app_test.ts", () => {
     });
     Rhum.testCase("Returns false", () => {
       // Assert the value has changes as the hook should have ran
-      Rhum.asserts.assertEquals(case_val, 2)
-    })
+      Rhum.asserts.assertEquals(case_val, 2);
+    });
   });
 
   // Run the second test suite
@@ -45,4 +45,4 @@ Rhum.testPlan("app_test.ts", () => {
   });
 });
 
-Rhum.run();
\ No newline at end of file
+Rhum.run();
diff --git a/tests/integration/hooks/after_each_test.ts b/tests/integration/hooks/after_each_test.ts
index f5f9393b..afdad43b 100644
--- a/tests/integration/hooks/after_each_test.ts
+++ b/tests/integration/hooks/after_each_test.ts
@@ -26,8 +26,8 @@ Rhum.testPlan("app_test.ts", () => {
     });
     Rhum.testCase("Returns false", () => {
       // Assert the value has changes as the hook should have ran
-      Rhum.asserts.assertEquals(case_val, 2)
-    })
+      Rhum.asserts.assertEquals(case_val, 2);
+    });
   });
 
   // Run the second test suite
@@ -45,4 +45,4 @@ Rhum.testPlan("app_test.ts", () => {
   });
 });
 
-Rhum.run();
\ No newline at end of file
+Rhum.run();
diff --git a/tests/integration/hooks/before_all_test.ts b/tests/integration/hooks/before_all_test.ts
index 05e5c858..360c9006 100644
--- a/tests/integration/hooks/before_all_test.ts
+++ b/tests/integration/hooks/before_all_test.ts
@@ -23,12 +23,12 @@ Rhum.testPlan("app_test.ts", () => {
       suite_val = "Ed";
       // Assert the value has changed from 22 to 2
       Rhum.asserts.assertEquals(case_val, 2);
-      case_val = 22
+      case_val = 22;
     });
     Rhum.testCase("Returns false", () => {
       // Assert the value has changed from 22 to 2 (after setting it to 22 in the above case)
-      Rhum.asserts.assertEquals(case_val, 2)
-    })
+      Rhum.asserts.assertEquals(case_val, 2);
+    });
   });
 
   // Run the second test suite
@@ -45,4 +45,4 @@ Rhum.testPlan("app_test.ts", () => {
   });
 });
 
-Rhum.run();
\ No newline at end of file
+Rhum.run();
diff --git a/tests/integration/hooks/before_each_test.ts b/tests/integration/hooks/before_each_test.ts
index f8e0016b..4367cca6 100644
--- a/tests/integration/hooks/before_each_test.ts
+++ b/tests/integration/hooks/before_each_test.ts
@@ -20,11 +20,11 @@ Rhum.testPlan("app_test.ts", () => {
       Rhum.asserts.assertEquals(suite_val, "Eric");
       suite_val = "Ed";
       Rhum.asserts.assertEquals(case_val, 2);
-      case_val = 22
+      case_val = 22;
     });
     Rhum.testCase("Returns false", () => {
-      Rhum.asserts.assertEquals(case_val, 2)
-    })
+      Rhum.asserts.assertEquals(case_val, 2);
+    });
   });
 
   // Run the second test suite
@@ -40,4 +40,4 @@ Rhum.testPlan("app_test.ts", () => {
   });
 });
 
-Rhum.run();
\ No newline at end of file
+Rhum.run();
diff --git a/tests/unit/mod_test.ts b/tests/unit/mod_test.ts
index f10ddc26..58999362 100644
--- a/tests/unit/mod_test.ts
+++ b/tests/unit/mod_test.ts
@@ -54,8 +54,12 @@ Deno.test({
 Deno.test({
   name: "Unit | Rhum | testCase() | Runs a test without failing",
   async fn(): Promise<void> {
-    Rhum.testCase("Testing testCase", () => {
-      console.log("Running!");
+    Rhum.testPlan("test plan", () => {
+      Rhum.testSuite("test suite", () => {
+        Rhum.testCase("Testing testCase", () => {
+          console.log("Running!");
+        });
+      });
     });
   },
 });
diff --git a/tests/unit/test_case_test.ts b/tests/unit/test_case_test.ts
index 5a54ac0f..d0c9c83d 100644
--- a/tests/unit/test_case_test.ts
+++ b/tests/unit/test_case_test.ts
@@ -1,19 +1,22 @@
 import { asserts } from "../../deps.ts";
 import { TestCase } from "../../src/test_case.ts";
+import { ITestPlan } from "../../src/interfaces.ts";
 
 Deno.test({
   name: "Unit | TestCase | run() | Runs the test without failing",
   async fn(): Promise<void> {
-    const plan = {
-      "suite_1": {
-        cases: [{
-          name: "case_1",
-          new_name: "123 case_1",
-          testFn: function () {
-            asserts.assertEquals(true, true);
-          },
-        }],
-      },
+    const plan: ITestPlan = {
+      suites: {
+        "suite_1": {
+          cases: [{
+            name: "case_1",
+            new_name: "123 case_1",
+            testFn: function () {
+              asserts.assertEquals(true, true);
+            },
+          }],
+        },
+      }
     };
     const testCase = new TestCase(plan);
     await testCase.run();