Multiple google-beta providers?

Hello, I just updated to terraform v0.13 and have now the issue that terraform somehow wants to install two google-beta providers. Using the following configuration:

terraform {
	required_version = "~> 0.13.4"
	required_providers {
		google      = "~> 3.44.0"
		googlebeta = {
			source = "hashicorp/google-beta"
			version = "~> 3.44.0" # for enabling private services access
		}
	}
}

terraform init yields the following outputs:

...
Initializing provider plugins...
- Finding hashicorp/google-beta versions matching "~> 3.44.0"...
- Finding hashicorp/google versions matching "~> 3.44.0"...
- Finding latest version of -/google-beta...
- Installing hashicorp/google v3.44.0...
- Installed hashicorp/google v3.44.0 (signed by HashiCorp)
- Installing -/google-beta v3.44.0...
- Installed -/google-beta v3.44.0 (signed by HashiCorp)
- Installing hashicorp/google-beta v3.44.0...
- Installed hashicorp/google-beta v3.44.0 (signed by HashiCorp)

The following providers do not have any version constraints in configuration,
so the latest version was installed.

To prevent automatic upgrades to new major versions that may contain breaking
changes, we recommend adding version constraints in a required_providers block
in your configuration, with the constraint strings suggested below.

* -/google-beta: version = "~> 3.44.0"
...

where does the -/google-beta provider come from?

(my provider definitions look like this:

provider "google" {
}
provider "googlebeta" {
}