diff --git a/src/authenticator.rs b/src/authenticator.rs
index a47834d..4064b30 100644
--- a/src/authenticator.rs
+++ b/src/authenticator.rs
@@ -300,6 +300,7 @@ impl ServiceAccountAuthenticator {
 pub struct ApplicationDefaultCredentialsAuthenticator;
 impl ApplicationDefaultCredentialsAuthenticator {
     /// Try to build ServiceAccountFlowOpts from the environment
+    #[cfg(feature = "service_account")]
     pub async fn from_environment() -> Result<ServiceAccountFlowOpts, std::env::VarError> {
         let service_account_key =
             crate::read_service_account_key(std::env::var("GOOGLE_APPLICATION_CREDENTIALS")?)
@@ -314,6 +315,7 @@ impl ApplicationDefaultCredentialsAuthenticator {
 
     /// Use the builder pattern to deduce which model of authenticator should be used:
     /// Service account one or GCE instance metadata kind
+    #[cfg(feature = "service_account")]
     #[cfg(any(feature = "hyper-rustls", feature = "hyper-tls"))]
     #[cfg_attr(
         yup_oauth2_docsrs,
@@ -326,6 +328,7 @@ impl ApplicationDefaultCredentialsAuthenticator {
     }
 
     /// Use the builder pattern to deduce which model of authenticator should be used and allow providing a hyper client
+    #[cfg(feature = "service_account")]
     pub async fn with_client<C>(
         client: C,
         opts: ApplicationDefaultCredentialsFlowOpts,
@@ -351,6 +354,7 @@ where
     C: HyperClientBuilder,
 {
     /// Service account based authenticator signature
+    #[cfg(feature = "service_account")]
     ServiceAccount(AuthenticatorBuilder<C, ServiceAccountFlowOpts>),
     /// GCE Instance Metadata based authenticator signature
     InstanceMetadata(AuthenticatorBuilder<C, ApplicationDefaultCredentialsFlowOpts>),
diff --git a/src/helper.rs b/src/helper.rs
index a5254fe..6972c07 100644
--- a/src/helper.rs
+++ b/src/helper.rs
@@ -46,6 +46,7 @@ pub async fn read_service_account_key<P: AsRef<Path>>(path: P) -> io::Result<Ser
     parse_service_account_key(key)
 }
 
+#[cfg(feature = "service_account")]
 /// Read a service account key from a JSON string.
 pub fn parse_service_account_key<S: AsRef<[u8]>>(key: S) -> io::Result<ServiceAccountKey> {
     serde_json::from_slice(key.as_ref()).map_err(|e| {