diff --git a/internal/creds.go b/internal/creds.go
index e6c4fe90d4..5ea555ed01 100644
--- a/internal/creds.go
+++ b/internal/creds.go
@@ -127,7 +127,7 @@ func baseCreds(ctx context.Context, ds *DialSettings) (*google.Credentials, erro
 	if ds.Credentials != nil {
 		return ds.Credentials, nil
 	}
-	if ds.CredentialsJSON != nil {
+	if len(ds.CredentialsJSON) > 0 {
 		return credentialsFromJSON(ctx, ds.CredentialsJSON, ds)
 	}
 	if ds.CredentialsFile != "" {
diff --git a/internal/settings.go b/internal/settings.go
index 6d0c18e5a8..edba49af49 100644
--- a/internal/settings.go
+++ b/internal/settings.go
@@ -126,7 +126,7 @@ func (ds *DialSettings) Validate() error {
 	if ds.Credentials != nil {
 		nCreds++
 	}
-	if ds.CredentialsJSON != nil {
+	if len(ds.CredentialsJSON) > 0 {
 		nCreds++
 	}
 	if ds.CredentialsFile != "" {