diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 47228b5fe..46f203226 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -1,7 +1,7 @@
 jobs:
   - job: Windows
 
-    timeoutInMinutes: 80
+    timeoutInMinutes: 90
 
     pool:
       vmImage: windows-latest
diff --git a/beacon_chain.nimble b/beacon_chain.nimble
index 359917f80..b8a976bf9 100644
--- a/beacon_chain.nimble
+++ b/beacon_chain.nimble
@@ -58,6 +58,10 @@ task test, "Run all tests":
   # pieces of code get tested regularly. Increased test output verbosity is the
   # price we pay for that.
 
+  # Just the part of minimal config which explicitly differs from mainnet
+  buildAndRunBinary "test_fixture_const_sanity_check", "tests/official/", "-d:const_preset=minimal -d:ETH2_SPEC=\"v0.11.3\""
+  buildAndRunBinary "test_fixture_const_sanity_check", "tests/official/", "-d:const_preset=minimal -d:ETH2_SPEC=\"v0.12.1\" -d:BLS_ETH2_SPEC=\"v0.12.x\""
+
   # Mainnet config
   buildAndRunBinary "proto_array", "beacon_chain/fork_choice/", "-d:const_preset=mainnet -d:ETH2_SPEC=\"v0.12.1\" -d:BLS_ETH2_SPEC=\"v0.12.x\""
   buildAndRunBinary "fork_choice", "beacon_chain/fork_choice/", "-d:const_preset=mainnet -d:ETH2_SPEC=\"v0.12.1\" -d:BLS_ETH2_SPEC=\"v0.12.x\""
diff --git a/beacon_chain/spec/datatypes.nim b/beacon_chain/spec/datatypes.nim
index bfef91348..8ed56919f 100644
--- a/beacon_chain/spec/datatypes.nim
+++ b/beacon_chain/spec/datatypes.nim
@@ -55,18 +55,16 @@ const const_preset* {.strdefine.} = "mainnet"
 
 when const_preset == "mainnet":
   when ETH2_SPEC == "v0.12.1":
-    import ./presets/mainnet
-    export mainnet
+    import ./presets/v0_12_1/mainnet
   else:
-    import ./presets/mainnet_v0_11_3
-    export mainnet_v0_11_3
+    import ./presets/v0_11_3/mainnet
+  export mainnet
 elif const_preset == "minimal":
   when ETH2_SPEC == "v0.12.1":
-    import ./presets/minimal
-    export minimal
+    import ./presets/v0_12_1/minimal
   else:
-    import ./presets/minimal_v0_11_3
-    export minimal_v0_11_3
+    import ./presets/v0_11_3/minimal
+  export minimal
 else:
   type
     Slot* = distinct uint64
diff --git a/beacon_chain/spec/helpers.nim b/beacon_chain/spec/helpers.nim
index 6d9416df6..2526cb3fa 100644
--- a/beacon_chain/spec/helpers.nim
+++ b/beacon_chain/spec/helpers.nim
@@ -166,7 +166,7 @@ func compute_domain*(
   result[0..3] = int_to_bytes4(domain_type.uint64)
   result[4..31] = fork_data_root.data[0..27]
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.11.3/specs/phase0/beacon-chain.md#get_domain
+# https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/beacon-chain.md#get_domain
 func get_domain*(
     fork: Fork, domain_type: DomainType, epoch: Epoch, genesis_validators_root: Eth2Digest): Domain =
   ## Return the signature domain (fork version concatenated with domain type)
diff --git a/beacon_chain/spec/presets/mainnet_v0_11_3.nim b/beacon_chain/spec/presets/v0_11_3/mainnet.nim
similarity index 100%
rename from beacon_chain/spec/presets/mainnet_v0_11_3.nim
rename to beacon_chain/spec/presets/v0_11_3/mainnet.nim
diff --git a/beacon_chain/spec/presets/minimal_v0_11_3.nim b/beacon_chain/spec/presets/v0_11_3/minimal.nim
similarity index 100%
rename from beacon_chain/spec/presets/minimal_v0_11_3.nim
rename to beacon_chain/spec/presets/v0_11_3/minimal.nim
diff --git a/beacon_chain/spec/presets/mainnet.nim b/beacon_chain/spec/presets/v0_12_1/mainnet.nim
similarity index 100%
rename from beacon_chain/spec/presets/mainnet.nim
rename to beacon_chain/spec/presets/v0_12_1/mainnet.nim
diff --git a/beacon_chain/spec/presets/minimal.nim b/beacon_chain/spec/presets/v0_12_1/minimal.nim
similarity index 100%
rename from beacon_chain/spec/presets/minimal.nim
rename to beacon_chain/spec/presets/v0_12_1/minimal.nim
diff --git a/tests/official/test_fixture_const_sanity_check.nim b/tests/official/test_fixture_const_sanity_check.nim
index d4b02dba9..aa67ce14e 100644
--- a/tests/official/test_fixture_const_sanity_check.nim
+++ b/tests/official/test_fixture_const_sanity_check.nim
@@ -80,12 +80,14 @@ macro parseNumConsts(file: static string): untyped =
 
   result = quote do: `constsToCheck`
 
-const datatypesConsts = @(parseNumConsts(SpecDir/"datatypes.nim"))
+const
+  datatypesConsts = @(parseNumConsts(SpecDir/"datatypes.nim"))
+  specVersionPresetDir = SpecDir/"presets"/("v"&replace(SPEC_VERSION, ".", "_"))
 
 when const_preset == "minimal":
-  const minimalConsts = @(parseNumConsts(SpecDir/"presets"/"minimal.nim"))
+  const minimalConsts = @(parseNumConsts(specVersionPresetDir/"minimal.nim"))
 else:
-  const mainnetConsts = @(parseNumConsts(SpecDir/"presets"/"mainnet.nim"))
+  const mainnetConsts = @(parseNumConsts(specVersionPresetDir/"mainnet.nim"))
 
 const IgnoreKeys = [
   # Ignore all non-numeric types