Anyone seen this error before:

pulumi:providers:aws (serverless-mono-shared-dev-targetaccount):
    error: rpc error: code = Unknown desc = could not validate provider configuration: 1 error occurred:
    	* assume_role.0: expected object, got string

Provider looks like this

export const deploymentProvider = new aws.Provider(
    `${projectName}-${environment}-targetaccount`,
    {
        region: awsConfig.require('region') as any,
        assumeRole: {
            roleArn: roleArnToAssume,
        },
    },
)

Role is pretty straight forward arnawssts:<account>role/Admin