diff --git a/pythclient/config.py b/pythclient/config.py
index 877d254..c9f1dbb 100644
--- a/pythclient/config.py
+++ b/pythclient/config.py
@@ -2,13 +2,13 @@
 Library-wide settings.
 """
 
-backoff_max_value = 16
-backoff_max_tries = 8
+BACKOFF_MAX_VALUE = 16
+BACKOFF_MAX_TRIES = 8
 
 # The following getter functions are passed to the backoff decorators
 
-def get_backoff_max_value():
-    return backoff_max_value
+def get_backoff_max_value() -> int:
+    return BACKOFF_MAX_VALUE
 
-def get_backoff_max_tries():
-    return backoff_max_tries
+def get_backoff_max_tries() -> int:
+    return BACKOFF_MAX_TRIES
diff --git a/pythclient/price_feeds.py b/pythclient/price_feeds.py
index 2dc337f..d5275f6 100644
--- a/pythclient/price_feeds.py
+++ b/pythclient/price_feeds.py
@@ -19,7 +19,7 @@
 
 
 class Price:
-    def __init__(self, conf, expo, price, publish_time):
+    def __init__(self, conf, expo, price, publish_time) -> None:
         self.conf = conf
         self.expo = expo
         self.price = price
@@ -38,7 +38,7 @@ def to_dict(self):
 
 
 class PriceUpdate:
-    def __init__(self, ema_price, price_id, price):
+    def __init__(self, ema_price, price_id, price) -> None:
         self.ema_price = ema_price
         self.id = price_id
         self.price = price
@@ -66,7 +66,7 @@ def __init__(
         last_attested_publish_time,
         price_feed,
         emitter_chain_id,
-    ):
+    ) -> None:
         self.seq_num = seq_num
         self.vaa = vaa
         self.publish_time = publish_time
@@ -117,7 +117,7 @@ def to_dict(self, verbose=False, vaa_format=DEFAULT_VAA_ENCODING):
 class MerkleUpdate:
     def __init__(
         self, message_size: int, message: bytes, proof_size: int, proof: List[bytes]
-    ):
+    ) -> None:
         self.message_size = message_size
         self.message = message
         self.proof_size = proof_size
@@ -142,7 +142,7 @@ def __init__(
         vaa: bytes,
         num_updates: int,
         updates: List[MerkleUpdate],
-    ):
+    ) -> None:
         self.magic = magic
         self.major_version = major_version
         self.minor_version = minor_version
@@ -195,7 +195,7 @@ def encode_vaa_for_chain(vaa: str, vaa_format: str, buffer=False) -> Union[bytes
 
 
 # Referenced from https://github.com/wormhole-foundation/wormhole/blob/main/sdk/js/src/vaa/wormhole.ts#L26-L56
-def parse_vaa(vaa, encoding):
+def parse_vaa(vaa: str, encoding: str) -> dict:
     vaa = cast(bytes, encode_vaa_for_chain(vaa, encoding, buffer=True))
 
     num_signers = vaa[5]
diff --git a/pythclient/pythaccounts.py b/pythclient/pythaccounts.py
index fa36598..a035c43 100644
--- a/pythclient/pythaccounts.py
+++ b/pythclient/pythaccounts.py
@@ -78,7 +78,7 @@ def _read_attribute_string(buffer: bytes, offset: int) -> Tuple[Optional[str], i
     return data.decode('utf8', 'replace'), data_end
 
 
-def _parse_header(buffer: bytes, offset: int = 0, *, key: SolanaPublicKeyOrStr):
+def _parse_header(buffer: bytes, offset: int = 0, *, key: SolanaPublicKeyOrStr) -> Tuple[PythAccountType, int, int]:
     if len(buffer) - offset < _ACCOUNT_HEADER_BYTES:
         raise ValueError("Pyth account data too short")