diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index a39f2dab1..a25db4a8e 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -12,7 +12,7 @@ import
   ./crypto, ./datatypes, ./digest, ./helpers, ./validator,
   ../../nbench/bench_lab
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.10.1/specs/phase0/beacon-chain.md#is_valid_merkle_branch
+# https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/beacon-chain.md#is_valid_merkle_branch
 func is_valid_merkle_branch*(leaf: Eth2Digest, branch: openarray[Eth2Digest], depth: uint64, index: uint64, root: Eth2Digest): bool {.nbench.}=
   ## Check if ``leaf`` at ``index`` verifies against the Merkle ``root`` and
   ## ``branch``.
@@ -398,7 +398,7 @@ proc is_valid_indexed_attestation*(
 
   true
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.10.1/specs/phase0/beacon-chain.md#get_attesting_indices
+# https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/beacon-chain.md#get_attesting_indices
 func get_attesting_indices*(state: BeaconState,
                             data: AttestationData,
                             bits: CommitteeValidatorsBits,
diff --git a/beacon_chain/spec/datatypes.nim b/beacon_chain/spec/datatypes.nim
index c82b00f59..1b2f336c0 100644
--- a/beacon_chain/spec/datatypes.nim
+++ b/beacon_chain/spec/datatypes.nim
@@ -370,7 +370,7 @@ type
     message*: AggregateAndProof
     signature*: ValidatorSig
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.10.1/specs/phase0/validator.md#eth1block
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/validator.md#eth1block
   Eth1Block* = object
     timestamp*: uint64
     # All other eth1 block fields
diff --git a/beacon_chain/spec/presets/mainnet.nim b/beacon_chain/spec/presets/mainnet.nim
index 5d2dc772c..b04ca11fa 100644
--- a/beacon_chain/spec/presets/mainnet.nim
+++ b/beacon_chain/spec/presets/mainnet.nim
@@ -73,7 +73,7 @@ const
 
   # Initial values
   # ---------------------------------------------------------------
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.10.1/configs/mainnet.yaml#L64
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/configs/mainnet.yaml#L70
   GENESIS_SLOT* = 0.Slot
   GENESIS_FORK_VERSION* = 0x00000000
   BLS_WITHDRAWAL_PREFIX* = 0'u8
@@ -145,7 +145,7 @@ const
 
   # Reward and penalty quotients
   # ---------------------------------------------------------------
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.10.1/configs/mainnet.yaml#L114
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/configs/mainnet.yaml#L117
   BASE_REWARD_FACTOR* = 2'u64^6
   WHISTLEBLOWER_REWARD_QUOTIENT* = 2'u64^9
   PROPOSER_REWARD_QUOTIENT* = 2'u64^3