diff --git a/src/services/modules/upgrade/upgrade-assert.services.ts b/src/services/modules/upgrade/upgrade-assert.services.ts
index f617c6e0..e03c966c 100644
--- a/src/services/modules/upgrade/upgrade-assert.services.ts
+++ b/src/services/modules/upgrade/upgrade-assert.services.ts
@@ -1,31 +1,9 @@
-import {isNullish, nonNullish} from '@dfinity/utils';
-import {satelliteBuildType, type BuildType, type SatelliteParameters} from '@junobuild/admin';
-import {gunzipFile, isGzip} from '@junobuild/cli-tools';
+import {isNullish} from '@dfinity/utils';
+import {satelliteBuildType, type SatelliteParameters} from '@junobuild/admin';
 import {cyan, yellow} from 'kleur';
 import type {AssertWasmModule, UpgradeWasm} from '../../../types/upgrade';
 import {NEW_CMD_LINE, confirmAndExit} from '../../../utils/prompt.utils';
-
-const wasmBuildType = async ({wasmModule}: AssertWasmModule): Promise<BuildType | undefined> => {
-  const buffer = Buffer.from(wasmModule);
-
-  const wasm = isGzip(buffer)
-    ? await gunzipFile({
-        source: buffer
-      })
-    : buffer;
-
-  const mod = new WebAssembly.Module(wasm);
-
-  const metadata = WebAssembly.Module.customSections(mod, 'icp:public juno:build');
-
-  const decoder = new TextDecoder();
-  const buildType = decoder.decode(metadata[0]);
-
-  return nonNullish(buildType) && ['stock', 'extended'].includes(buildType)
-    ? // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-      (buildType as BuildType)
-    : undefined;
-};
+import {readWasmModuleMetadata} from '../../../utils/wasm.utils';
 
 export const assertSatelliteBuildType = async ({
   satellite,
@@ -36,8 +14,8 @@ export const assertSatelliteBuildType = async ({
   const hideAgentJsConsoleWarn = globalThis.console.warn;
   globalThis.console.warn = (): null => null;
 
-  const [wasmTypeResult, satelliteTypeResult] = await Promise.allSettled([
-    wasmBuildType({wasmModule}),
+  const [wasmMetadataResult, satelliteTypeResult] = await Promise.allSettled([
+    readWasmModuleMetadata({wasmModule}),
     satelliteBuildType({
       satellite
     })
@@ -46,7 +24,7 @@ export const assertSatelliteBuildType = async ({
   // Redo console.warn
   globalThis.console.warn = hideAgentJsConsoleWarn;
 
-  if (wasmTypeResult.status === 'rejected') {
+  if (wasmMetadataResult.status === 'rejected') {
     throw new Error(`The custom sections of the WASM module you try to upgrade cannot be read.`);
   }
 
@@ -55,9 +33,11 @@ export const assertSatelliteBuildType = async ({
     return;
   }
 
-  const {value: wasmType} = wasmTypeResult;
+  const {value: wasmMetadata} = wasmMetadataResult;
   const {value: satelliteType} = satelliteTypeResult;
 
+  const {buildType: wasmType} = wasmMetadata;
+
   if (satelliteType === 'extended' && (wasmType === 'stock' || isNullish(wasmType))) {
     await confirmAndExit(
       `Your satellite is currently running on an ${cyan(
diff --git a/src/utils/wasm.utils.ts b/src/utils/wasm.utils.ts
new file mode 100644
index 00000000..bb5bb85d
--- /dev/null
+++ b/src/utils/wasm.utils.ts
@@ -0,0 +1,114 @@
+import {isNullish, nonNullish} from '@dfinity/utils';
+import {type BuildType, findJunoPackageDependency} from '@junobuild/admin';
+import {gunzipFile, isGzip} from '@junobuild/cli-tools';
+import {JUNO_PACKAGE_SATELLITE_ID, type JunoPackage, JunoPackageSchema} from '@junobuild/config';
+import {readFile} from 'node:fs/promises';
+import {uint8ArrayToString} from 'uint8array-extras';
+
+interface WasmMetadata {
+  gzipped: boolean;
+  junoPackage: JunoPackage | undefined;
+  buildType: BuildType | undefined;
+}
+
+export const readWasmFileMetadata = async ({path}: {path: string}): Promise<WasmMetadata> => {
+  const buffer = await readFile(path);
+  return await readWasmMetadata({buffer});
+};
+
+export const readWasmModuleMetadata = async ({
+  wasmModule
+}: {
+  wasmModule: Uint8Array;
+}): Promise<WasmMetadata> => {
+  const buffer = Buffer.from(wasmModule);
+  return await readWasmMetadata({buffer});
+};
+
+const readWasmMetadata = async ({buffer}: {buffer: Buffer}): Promise<WasmMetadata> => {
+  const gzipped = isGzip(buffer);
+
+  const wasm = gzipped
+    ? await gunzipFile({
+        source: buffer
+      })
+    : buffer;
+
+  const junoPackage = await readCustomSectionJunoPackage({wasm});
+
+  const buildType = await extractBuildType({wasm, junoPackage});
+
+  return {
+    gzipped,
+    junoPackage,
+    buildType
+  };
+};
+
+const extractBuildType = async ({
+  junoPackage,
+  wasm
+}: {
+  junoPackage: JunoPackage | undefined;
+  wasm: Buffer;
+}): Promise<BuildType | undefined> => {
+  if (isNullish(junoPackage)) {
+    return await readDeprecatedBuildType({wasm});
+  }
+
+  const {name, dependencies} = junoPackage;
+
+  if (name === JUNO_PACKAGE_SATELLITE_ID) {
+    return 'stock';
+  }
+
+  const satelliteDependency = findJunoPackageDependency({
+    dependencies,
+    dependencyId: JUNO_PACKAGE_SATELLITE_ID
+  });
+
+  return nonNullish(satelliteDependency) ? 'extended' : undefined;
+};
+
+/**
+ * @deprecated Modern WASM build use JunoPackage.
+ */
+const readDeprecatedBuildType = async ({wasm}: {wasm: Buffer}): Promise<BuildType | undefined> => {
+  const buildType = await customSection({wasm, sectionName: 'icp:public juno:build'});
+
+  return nonNullish(buildType) && ['stock', 'extended'].includes(buildType)
+    ? // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      (buildType as BuildType)
+    : undefined;
+};
+
+const readCustomSectionJunoPackage = async ({
+  wasm
+}: {
+  wasm: Buffer;
+}): Promise<JunoPackage | undefined> => {
+  const section = await customSection({wasm, sectionName: 'icp:public juno:package'});
+
+  if (isNullish(section)) {
+    return undefined;
+  }
+
+  const {success, data} = JunoPackageSchema.safeParse(section);
+  return success ? data : undefined;
+};
+
+const customSection = async ({
+  sectionName,
+  wasm
+}: {
+  sectionName: string;
+  wasm: Buffer;
+}): Promise<string | undefined> => {
+  const wasmModule = await WebAssembly.compile(wasm);
+
+  const pkgSections = WebAssembly.Module.customSections(wasmModule, sectionName);
+
+  const [pkgBuffer] = pkgSections;
+
+  return nonNullish(pkgBuffer) ? uint8ArrayToString(pkgBuffer) : undefined;
+};