diff --git a/packages/nx/src/utils/command-line-utils.spec.ts b/packages/nx/src/utils/command-line-utils.spec.ts
index c68058a47f437..78794ca4c0940 100644
--- a/packages/nx/src/utils/command-line-utils.spec.ts
+++ b/packages/nx/src/utils/command-line-utils.spec.ts
@@ -161,6 +161,24 @@ describe('splitArgs', () => {
     });
   });
 
+  it('should split projects when it is a string', () => {
+    expect(
+      splitArgsIntoNxArgsAndOverrides(
+        {
+          projects: 'aaa,bbb',
+          __overrides_unparsed__: [],
+          $0: '',
+        },
+        'run-many',
+        {} as any,
+        {} as any
+      ).nxArgs
+    ).toEqual({
+      projects: ['aaa', 'bbb'],
+      skipNxCache: false,
+    });
+  });
+
   it('should set base and head based on environment variables in affected mode, if they are not provided directly on the command', () => {
     const originalNxBase = process.env.NX_BASE;
     process.env.NX_BASE = 'envVarSha1';
diff --git a/packages/nx/src/utils/command-line-utils.ts b/packages/nx/src/utils/command-line-utils.ts
index d806ca7e4c57c..eed9b713569f3 100644
--- a/packages/nx/src/utils/command-line-utils.ts
+++ b/packages/nx/src/utils/command-line-utils.ts
@@ -81,8 +81,11 @@ export function splitArgsIntoNxArgsAndOverrides(
   delete (nxArgs as any).__overrides_unparsed__;
 
   if (mode === 'run-many') {
-    if (!nxArgs.projects) {
-      nxArgs.projects = [];
+    const args = nxArgs as any;
+    if (!args.projects) {
+      args.projects = [];
+    } else if (typeof args.projects === 'string') {
+      args.projects = args.projects.split(',');
     }
   }