diff --git a/README.md b/README.md
index f3e7505..259e183 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ import { create } from '@emscripten-forge/mambajs';
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - python=3.11
@@ -297,7 +297,7 @@ npx lerna version --no-private
 Mambajs is designed primarily for WebAssembly/Emscripten environments but can work in Node.js for lock file manipulation.
 
 **Default Platform**: `emscripten-wasm32`
-**Default Channels**: `emscripten-forge` (https://prefix.dev/emscripten-forge-dev), `conda-forge` (https://prefix.dev/conda-forge)
+**Default Channels**: `emscripten-forge` (https://prefix.dev/emscripten-forge-3x), `conda-forge` (https://prefix.dev/conda-forge)
 
 ## License
 
diff --git a/packages/mambajs-core/src/helper.ts b/packages/mambajs-core/src/helper.ts
index 677c7cf..dd827ad 100644
--- a/packages/mambajs-core/src/helper.ts
+++ b/packages/mambajs-core/src/helper.ts
@@ -4,6 +4,7 @@ import {
   DEFAULT_CHANNELS,
   DEFAULT_CHANNELS_INFO,
   ILock,
+  ILogger,
   ISolvedPackage,
   TSharedLibs
 } from './types';
@@ -468,8 +469,13 @@ export function getCondaMetaFile(
 }
 
 export function formatChannels(
-  channels?: string[]
+  channels?: string[],
+  logger?: ILogger
 ): Pick<ILock, 'channelInfo' | 'channels'> {
+  if (!logger) {
+    logger = console;
+  }
+
   if (!channels || !channels.length) {
     throw new Error('No channels specified');
   }
@@ -520,6 +526,17 @@ export function formatChannels(
       return;
     }
 
+    if (channel === 'emscripten-forge') {
+      logger.warn('emscripten-forge channel alias is deprecated. Please use https://prefix.dev/emscripten-forge-3x explicitely.')
+      channel = 'https://prefix.dev/emscripten-forge-3x';
+    }
+
+    if (channel === 'https://prefix.dev/emscripten-forge') {
+      const error = 'https://prefix.dev/emscripten-forge channel does not exist. Please use https://prefix.dev/emscripten-forge-3x or https://prefix.dev/emscripten-forge-4x explicitely.';
+      logger.error(error)
+      throw new Error(error);
+    }
+
     // If it's one of the default channels and it's not included yet, add it
     const asDefaultChannel = getDefaultChannel(channel);
     if (
diff --git a/packages/mambajs-core/src/types.ts b/packages/mambajs-core/src/types.ts
index 1afc866..2cf2cb0 100644
--- a/packages/mambajs-core/src/types.ts
+++ b/packages/mambajs-core/src/types.ts
@@ -21,17 +21,27 @@ export type ISolvedPipPackages = ILock['pipPackages'];
 
 export const DEFAULT_PLATFORM: ILock['platform'] = 'emscripten-wasm32';
 export const DEFAULT_CHANNELS: ILock['channels'] = [
-  'emscripten-forge',
+  'emscripten-forge-4x',
   'conda-forge'
 ];
 export const DEFAULT_CHANNELS_INFO: ILock['channelInfo'] = {
-  'emscripten-forge': [
+  'emscripten-forge-4x': [
     {
-      url: 'https://prefix.dev/emscripten-forge-dev',
+      url: 'https://prefix.dev/emscripten-forge-4x',
       protocol: 'https'
     },
     {
-      url: 'https://repo.prefix.dev/emscripten-forge-dev',
+      url: 'https://repo.prefix.dev/emscripten-forge-4x',
+      protocol: 'https'
+    }
+  ],
+  'emscripten-forge-3x': [
+    {
+      url: 'https://prefix.dev/emscripten-forge-3x',
+      protocol: 'https'
+    },
+    {
+      url: 'https://repo.prefix.dev/emscripten-forge-3x',
       protocol: 'https'
     }
   ],
diff --git a/packages/mambajs/src/index.ts b/packages/mambajs/src/index.ts
index 112dd55..0a45d48 100644
--- a/packages/mambajs/src/index.ts
+++ b/packages/mambajs/src/index.ts
@@ -162,7 +162,7 @@ export async function install(
 
   if (channels?.length) {
     // Merge existing channels with new ones
-    const newChannels = formatChannels(channels);
+    const newChannels = formatChannels(channels, logger);
 
     for (const channel of newChannels.channels) {
       if (!env.channels.includes(channel)) {
diff --git a/packages/mambajs/src/solver.ts b/packages/mambajs/src/solver.ts
index b05182a..594eb4d 100644
--- a/packages/mambajs/src/solver.ts
+++ b/packages/mambajs/src/solver.ts
@@ -60,7 +60,7 @@ export const solveConda = async (options: ISolveOptions): Promise<ILock> => {
   if (typeof ymlOrSpecs === 'string') {
     const ymlData = parseEnvYml(ymlOrSpecs);
     specs = ymlData.specs;
-    formattedChannels = formatChannels(ymlData.channels);
+    formattedChannels = formatChannels(ymlData.channels, logger);
   } else {
     installedCondaPackages = currentLock?.packages ?? {};
     formattedChannels = currentLock!;
diff --git a/unittests/tests/conda/test-cpp.ts b/unittests/tests/conda/test-cpp.ts
index d45dc7d..4385763 100644
--- a/unittests/tests/conda/test-cpp.ts
+++ b/unittests/tests/conda/test-cpp.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - xeus-cpp
diff --git a/unittests/tests/conda/test-solver.ts b/unittests/tests/conda/test-solver.ts
index d871500..967aae4 100644
--- a/unittests/tests/conda/test-solver.ts
+++ b/unittests/tests/conda/test-solver.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - pandas
diff --git a/unittests/tests/conda/test-virtual-packages.ts b/unittests/tests/conda/test-virtual-packages.ts
index 93222c1..a626bed 100644
--- a/unittests/tests/conda/test-virtual-packages.ts
+++ b/unittests/tests/conda/test-virtual-packages.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 let yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   # click requires __unix
diff --git a/unittests/tests/format/test-format.ts b/unittests/tests/format/test-format.ts
index 38c8eca..77552f0 100644
--- a/unittests/tests/format/test-format.ts
+++ b/unittests/tests/format/test-format.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - pandas
diff --git a/unittests/tests/mixed/test-create-channel-alias.ts b/unittests/tests/mixed/test-create-channel-alias.ts
index 4924d12..e8419ba 100644
--- a/unittests/tests/mixed/test-create-channel-alias.ts
+++ b/unittests/tests/mixed/test-create-channel-alias.ts
@@ -38,4 +38,7 @@ create({yml, logger}).then(async result => {
 
   expect(condaPackages['ipycanvas'].version).toEqual('0.13.2');
   expect(pipPackages['bqplot'].version).toEqual('0.12.42');
+
+  // Channel alias is deprecated
+  expect(logger.warnings).toInclude('deprecated');
 });
diff --git a/unittests/tests/mixed/test-create-emscripten-4x.ts b/unittests/tests/mixed/test-create-emscripten-4x.ts
index 2909768..8783f42 100644
--- a/unittests/tests/mixed/test-create-emscripten-4x.ts
+++ b/unittests/tests/mixed/test-create-emscripten-4x.ts
@@ -42,7 +42,7 @@ create({yml, logger}).then(async env => {
   expect(condaPackages['ipycanvas'].version).toEqual('0.13.2');
 
   // Make sure channels haven't changed
-  expect(env.channels).toEqual(['https://repo.prefix.dev/emscripten-forge-4x', 'conda-forge']);
+  expect(env.channels).toEqual(['emscripten-forge-4x', 'conda-forge']);
 
   // Make sure we keep the emscripten version
   expect(condaPackages['emscripten-abi'].version[0]).toEqual('4');
diff --git a/unittests/tests/mixed/test-create.ts b/unittests/tests/mixed/test-create.ts
index d9ab48c..9caa07f 100644
--- a/unittests/tests/mixed/test-create.ts
+++ b/unittests/tests/mixed/test-create.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - pandas
diff --git a/unittests/tests/mixed/test-install.ts b/unittests/tests/mixed/test-install.ts
index f0567c7..3307b0c 100644
--- a/unittests/tests/mixed/test-install.ts
+++ b/unittests/tests/mixed/test-install.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - pandas
diff --git a/unittests/tests/mixed/test-install2.ts b/unittests/tests/mixed/test-install2.ts
index 945a4dd..a4db3b3 100644
--- a/unittests/tests/mixed/test-install2.ts
+++ b/unittests/tests/mixed/test-install2.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://repo.prefix.dev/emscripten-forge-dev
+  - https://repo.prefix.dev/emscripten-forge-3x
   - https://repo.prefix.dev/conda-forge
 dependencies:
   - pandas
diff --git a/unittests/tests/mixed/test-remove.ts b/unittests/tests/mixed/test-remove.ts
index bd95359..d29f30c 100644
--- a/unittests/tests/mixed/test-remove.ts
+++ b/unittests/tests/mixed/test-remove.ts
@@ -7,7 +7,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - pandas
diff --git a/unittests/tests/mixed/test-solver.ts b/unittests/tests/mixed/test-solver.ts
index d939799..e349795 100644
--- a/unittests/tests/mixed/test-solver.ts
+++ b/unittests/tests/mixed/test-solver.ts
@@ -6,7 +6,7 @@ const logger = new TestLogger();
 
 const yml = `
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-3x
   - https://prefix.dev/conda-forge
 dependencies:
   - pandas