diff --git a/src/utils/normalize-options.js b/src/utils/normalize-options.js
index fe4dd3a..de4d7ee 100644
--- a/src/utils/normalize-options.js
+++ b/src/utils/normalize-options.js
@@ -60,50 +60,6 @@ function parseFlags(options) {
     }
   });
 
-  let legacyEnvFlags = options.envFlags;
-  if (legacyEnvFlags) {
-    let source = legacyEnvFlags.source;
-    combinedFlags[source] = combinedFlags[source] || {};
-
-    for (let flagName in legacyEnvFlags.flags) {
-      let flagValue = legacyEnvFlags.flags[flagName];
-      combinedFlags[source][flagName] = evaluateFlagValue(options, null, flagName, flagValue);
-    }
-  }
-
-  let legacyFeatures = options.features;
-  if (legacyFeatures) {
-    if (!Array.isArray(legacyFeatures)) {
-      legacyFeatures = [legacyFeatures];
-    }
-
-    legacyFeatures.forEach((flagsDefinition) => {
-      let source = flagsDefinition.source;
-      let flagsForSource = (combinedFlags[source] = combinedFlags[source] || {});
-
-      for (let flagName in flagsDefinition.flags) {
-        let flagValue = flagsDefinition.flags[flagName];
-
-        flagsForSource[flagName] = evaluateFlagValue(
-          options,
-          flagsDefinition.name,
-          flagName,
-          flagValue
-        );
-      }
-    });
-  }
-
-  if (legacyFeatures || legacyEnvFlags) {
-    let msg = `[babel-plugin-debug-macros]: passed v1 configuration, converting to v2.  Legacy configuration passed:\n${JSON.stringify(
-      options,
-      null,
-      2
-    )}`;
-
-    console.warn(msg);
-  }
-
   return combinedFlags;
 }
 
diff --git a/tests/create-tests.js b/tests/create-tests.js
index 80c43e1..979d698 100644
--- a/tests/create-tests.js
+++ b/tests/create-tests.js
@@ -173,63 +173,28 @@ function createTests(options) {
   });
 
   describe('ember-cli-babel configuration', function () {
-    describe('Ember < 3.27', function () {
-      describe('legacy config API', function () {
-        beforeEach(function () {
-          console.warn = () => {};
-        });
-
-        let h = transformTestHelper({
-          presets,
-          plugins: [
-            [
-              DebugToolsPlugin,
-              {
-                externalizeHelpers: {
-                  global: 'Ember',
-                },
-                debugTools: {
-                  isDebug: true,
-                  source: '@ember/debug',
-                  assertPredicateIndex: 1,
-                },
-                envFlags: {
-                  source: '@glimmer/env',
-                  flags: {
-                    DEBUG: true,
-                  },
-                },
+    describe('default configuration', function () {
+      let h = transformTestHelper({
+        presets,
+        plugins: [
+          [
+            DebugToolsPlugin,
+            {
+              externalizeHelpers: {
+                global: 'Ember',
               },
-            ],
-          ],
-        });
-
-        h.generateTest('ember-cli-babel-config-pre-3-27');
-      });
-
-      describe('default configuration', function () {
-        let h = transformTestHelper({
-          presets,
-          plugins: [
-            [
-              DebugToolsPlugin,
-              {
-                externalizeHelpers: {
-                  global: 'Ember',
-                },
-                debugTools: {
-                  isDebug: true,
-                  source: '@ember/debug',
-                  assertPredicateIndex: 1,
-                },
-                flags: [{ source: '@glimmer/env', flags: { DEBUG: true } }],
+              debugTools: {
+                isDebug: true,
+                source: '@ember/debug',
+                assertPredicateIndex: 1,
               },
-            ],
+              flags: [{ source: '@glimmer/env', flags: { DEBUG: true } }],
+            },
           ],
-        });
-
-        h.generateTest('ember-cli-babel-config-pre-3-27');
+        ],
       });
+
+      h.generateTest('ember-cli-babel-config-pre-3-27');
     });
 
     describe('Ember >= 3.27', function () {
diff --git a/tests/normalize-options-test.js b/tests/normalize-options-test.js
index 47d1e8f..7614927 100644
--- a/tests/normalize-options-test.js
+++ b/tests/normalize-options-test.js
@@ -26,55 +26,6 @@ describe('normalizeOptions', function () {
     expect(actual).toEqual(expected);
   });
 
-  it('converts "old style" options into the newer style (with deprecation)', function () {
-    let warnings = [];
-    console.warn = warning => warnings.push(warning); // eslint-disable-line
-
-    let options = {
-      envFlags: {
-        source: '@ember/env-flags',
-        flags: {
-          DEBUG: false,
-        },
-      },
-      debugTools: {
-        source: '@ember/debug-tools',
-      },
-      features: {
-        name: 'ember-source',
-        source: '@ember/features',
-        flags: {
-          FEATURE_A: true,
-          FEATURE_B: null,
-        },
-      },
-    };
-    let stringifiedOptions = JSON.stringify(options, null, 2);
-    let actual = normalizeOptions(options);
-    let expected = {
-      debugTools: {
-        isDebug: false,
-        assertPredicateIndex: undefined,
-        debugToolsImport: '@ember/debug-tools',
-      },
-      flags: {
-        '@ember/env-flags': {
-          DEBUG: false,
-        },
-        '@ember/features': {
-          FEATURE_A: true,
-          FEATURE_B: null,
-        },
-      },
-      externalizeHelpers: undefined,
-    };
-
-    expect(actual).toEqual(expected);
-    expect(warnings).toEqual([
-      `[babel-plugin-debug-macros]: passed v1 configuration, converting to v2.  Legacy configuration passed:\n${stringifiedOptions}`,
-    ]);
-  });
-
   it('sets flag to false when svelte version matches the flag version', function () {
     let actual = normalizeOptions({
       debugTools: {