diff --git a/README.md b/README.md
index 61600d389..9f2528263 100644
--- a/README.md
+++ b/README.md
@@ -20,11 +20,11 @@ Features are researched and developed in parallel, and then consolidated into se
 | 0 | **Phase0** |`0` | <ul><li>Core</li><ul><li>[The beacon chain](specs/phase0/beacon-chain.md)</li><li>[Deposit contract](specs/phase0/deposit-contract.md)</li><li>[Beacon chain fork choice](specs/phase0/fork-choice.md)</li></ul><li>Additions</li><ul><li>[Honest validator guide](specs/phase0/validator.md)</li><li>[P2P networking](specs/phase0/p2p-interface.md)</li><li>[Weak subjectivity](specs/phase0/weak-subjectivity.md)</li></ul></ul> |
 | 1 |  **Altair** | `74240` | <ul><li>Core</li><ul><li>[Beacon chain changes](specs/altair/beacon-chain.md)</li><li>[Altair fork](specs/altair/fork.md)</li></ul><li>Additions</li><ul><li>[Light client sync protocol](specs/altair/light-client/sync-protocol.md) ([full node](specs/altair/light-client/full-node.md), [light client](specs/altair/light-client/light-client.md), [networking](specs/altair/light-client/p2p-interface.md))</li><li>[Honest validator guide changes](specs/altair/validator.md)</li><li>[P2P networking](specs/altair/p2p-interface.md)</li></ul></ul> |
 | 2 | **Bellatrix** <br/> (["The Merge"](https://ethereum.org/en/upgrades/merge/)) | `144896` | <ul><li>Core</li><ul><li>[Beacon Chain changes](specs/bellatrix/beacon-chain.md)</li><li>[Bellatrix fork](specs/bellatrix/fork.md)</li><li>[Fork choice changes](specs/bellatrix/fork-choice.md)</li></ul><li>Additions</li><ul><li>[Honest validator guide changes](specs/bellatrix/validator.md)</li><li>[P2P networking](specs/bellatrix/p2p-interface.md)</li></ul></ul> |
+| 3 | **Capella** | `194048` | <ul><li>Core</li><ul><li>[Beacon chain changes](specs/capella/beacon-chain.md)</li><li>[Capella fork](specs/capella/fork.md)</li></ul><li>Additions</li><ul><li>[Light client sync protocol changes](specs/capella/light-client/sync-protocol.md) ([fork](specs/capella/light-client/fork.md), [full node](specs/capella/light-client/full-node.md), [networking](specs/capella/light-client/p2p-interface.md))</li></ul><ul><li>[Validator additions](specs/capella/validator.md)</li><li>[P2P networking](specs/capella/p2p-interface.md)</li></ul></ul> |
 
 ### In-development Specifications
 | Code Name or Topic | Specs | Notes |
 | - | - | - |
-| Capella (tentative) | <ul><li>Core</li><ul><li>[Beacon chain changes](specs/capella/beacon-chain.md)</li><li>[Capella fork](specs/capella/fork.md)</li></ul><li>Additions</li><ul><li>[Light client sync protocol changes](specs/capella/light-client/sync-protocol.md) ([fork](specs/capella/light-client/fork.md), [full node](specs/capella/light-client/full-node.md), [networking](specs/capella/light-client/p2p-interface.md))</li></ul><ul><li>[Validator additions](specs/capella/validator.md)</li><li>[P2P networking](specs/capella/p2p-interface.md)</li></ul></ul> |
 | Deneb (tentative) | <ul><li>Core</li><ul><li>[Beacon Chain changes](specs/deneb/beacon-chain.md)</li><li>[Deneb fork](specs/deneb/fork.md)</li><li>[Polynomial commitments](specs/deneb/polynomial-commitments.md)</li><li>[Fork choice changes](specs/deneb/fork-choice.md)</li></ul><li>Additions</li><ul><li>[Light client sync protocol changes](specs/deneb/light-client/sync-protocol.md) ([fork](specs/deneb/light-client/fork.md), [full node](specs/deneb/light-client/full-node.md), [networking](specs/deneb/light-client/p2p-interface.md))</li></ul><ul><li>[Honest validator guide changes](specs/deneb/validator.md)</li><li>[P2P networking](specs/deneb/p2p-interface.md)</li></ul></ul> |
 | Sharding (outdated) | <ul><li>Core</li><ul><li>[Beacon Chain changes](specs/_features/sharding/beacon-chain.md)</li></ul><li>Additions</li><ul><li>[P2P networking](specs/_features/sharding/p2p-interface.md)</li></ul></ul> |
 | Custody Game (outdated) | <ul><li>Core</li><ul><li>[Beacon Chain changes](specs/_features/custody_game/beacon-chain.md)</li></ul><li>Additions</li><ul><li>[Honest validator guide changes](specs/_features/custody_game/validator.md)</li></ul></ul> | Dependent on sharding |
diff --git a/configs/mainnet.yaml b/configs/mainnet.yaml
index f7e53d7e1..f204d1746 100644
--- a/configs/mainnet.yaml
+++ b/configs/mainnet.yaml
@@ -46,7 +46,7 @@ BELLATRIX_FORK_VERSION: 0x02000000
 BELLATRIX_FORK_EPOCH: 144896  # Sept 6, 2022, 11:34:47am UTC
 # Capella
 CAPELLA_FORK_VERSION: 0x03000000
-CAPELLA_FORK_EPOCH: 18446744073709551615
+CAPELLA_FORK_EPOCH: 194048  # April 12, 2023, 10:27:35pm UTC
 # Deneb
 DENEB_FORK_VERSION: 0x04000000
 DENEB_FORK_EPOCH: 18446744073709551615
diff --git a/specs/capella/fork.md b/specs/capella/fork.md
index 49bf8744f..95bdf79ae 100644
--- a/specs/capella/fork.md
+++ b/specs/capella/fork.md
@@ -27,7 +27,7 @@ Warning: this configuration is not definitive.
 | Name | Value |
 | - | - |
 | `CAPELLA_FORK_VERSION` | `Version('0x03000000')` |
-| `CAPELLA_FORK_EPOCH` | `Epoch(18446744073709551615)` **TBD** |
+| `CAPELLA_FORK_EPOCH` | `Epoch(194048)` (April 12, 2023, 10:27:35pm UTC) |
 
 
 ## Helper functions
diff --git a/specs/deneb/polynomial-commitments.md b/specs/deneb/polynomial-commitments.md
index c48857d9e..e23c31fab 100644
--- a/specs/deneb/polynomial-commitments.md
+++ b/specs/deneb/polynomial-commitments.md
@@ -252,10 +252,11 @@ def compute_challenge(blob: Blob,
 ```python
 def bls_modular_inverse(x: BLSFieldElement) -> BLSFieldElement:
     """
-    Compute the modular inverse of x
-    i.e. return y such that x * y % BLS_MODULUS == 1 and return 0 for x == 0
+    Compute the modular inverse of x (for x != 0)
+    i.e. return y such that x * y % BLS_MODULUS == 1
     """
-    return BLSFieldElement(pow(x, -1, BLS_MODULUS)) if x != 0 else BLSFieldElement(0)
+    assert (int(x) % BLS_MODULUS) != 0
+    return BLSFieldElement(pow(x, -1, BLS_MODULUS))
 ```
 
 #### `div`
diff --git a/tests/core/pyspec/eth2spec/VERSION.txt b/tests/core/pyspec/eth2spec/VERSION.txt
index 9b388ed89..d4f06976f 100644
--- a/tests/core/pyspec/eth2spec/VERSION.txt
+++ b/tests/core/pyspec/eth2spec/VERSION.txt
@@ -1 +1 @@
-1.3.0-rc.4
+1.3.0-rc.5
diff --git a/tests/core/pyspec/eth2spec/test/deneb/unittests/polynomial_commitments/test_polynomial_commitments.py b/tests/core/pyspec/eth2spec/test/deneb/unittests/polynomial_commitments/test_polynomial_commitments.py
index f42f88393..7d89a9788 100644
--- a/tests/core/pyspec/eth2spec/test/deneb/unittests/polynomial_commitments/test_polynomial_commitments.py
+++ b/tests/core/pyspec/eth2spec/test/deneb/unittests/polynomial_commitments/test_polynomial_commitments.py
@@ -215,6 +215,29 @@ def test_verify_blob_kzg_proof_incorrect_proof(spec):
     assert not spec.verify_blob_kzg_proof(blob, commitment, proof)
 
 
+@with_deneb_and_later
+@spec_test
+@single_phase
+def test_bls_modular_inverse(spec):
+    """
+    Verify computation of multiplicative inverse
+    """
+    rng = random.Random(5566)
+
+    # Should fail for x == 0
+    expect_assertion_error(lambda: spec.bls_modular_inverse(0))
+    expect_assertion_error(lambda: spec.bls_modular_inverse(spec.BLS_MODULUS))
+    expect_assertion_error(lambda: spec.bls_modular_inverse(2 * spec.BLS_MODULUS))
+
+    # Test a trivial inversion
+    assert 1 == int(spec.bls_modular_inverse(1))
+
+    # Test a random inversion
+    r = rng.randint(0, spec.BLS_MODULUS - 1)
+    r_inv = int(spec.bls_modular_inverse(r))
+    assert r * r_inv % BLS_MODULUS == 1
+
+
 @with_deneb_and_later
 @spec_test
 @single_phase