diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 489cd48dd..11e4bcbe1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -115,7 +115,7 @@ jobs:
 
           # libminiupnp / natpmp
           if [[ '${{ runner.os }}' == 'Linux' && '${{ matrix.target.cpu }}' == 'i386' ]]; then
-            export CFLAGS="${CFLAGS} -m32"
+            export CFLAGS="${CFLAGS} -m32 -mno-adx"
             echo "::set-env name=CFLAGS::$CFLAGS"
           fi
         env:
@@ -131,11 +131,11 @@ jobs:
           mkdir -p external/bin
           cat << EOF > external/bin/gcc
           #!/bin/bash
-          exec $(which gcc) -m32 "\$@"
+          exec $(which gcc) -m32 -mno-adx "\$@"
           EOF
           cat << EOF > external/bin/g++
           #!/bin/bash
-          exec $(which g++) -m32 "\$@"
+          exec $(which g++) -m32 -mno-adx "\$@"
           EOF
           chmod 755 external/bin/gcc external/bin/g++
           echo '::add-path::${{ github.workspace }}/external/bin'
diff --git a/beacon_chain.nimble b/beacon_chain.nimble
index 2d4ce630e..a3fd1097b 100644
--- a/beacon_chain.nimble
+++ b/beacon_chain.nimble
@@ -80,13 +80,15 @@ task test, "Run all tests":
   # TODO `test_keystore` is extracted from the rest of the tests because it uses conflicting BLST headers
   buildAndRunBinary "test_keystore", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:chronicles_sinks="json[file]""""
 
-  # Check Miracl/Milagro fallback on select tests
-  buildAndRunBinary "test_interop", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
-  buildAndRunBinary "test_process_attestation", "tests/spec_block_processing/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
-  buildAndRunBinary "test_process_deposits", "tests/spec_block_processing/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
-  buildAndRunBinary "all_fixtures_require_ssz", "tests/official/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
-  buildAndRunBinary "test_attestation_pool", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
-  buildAndRunBinary "test_block_pool", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
+  # As BLST has a pure C fallback as of Dec 2020 undergoing audit and formal verification
+  # we skip Miracl checks as they are costly in CI time.
+  # # Check Miracl/Milagro fallback on select tests
+  # buildAndRunBinary "test_interop", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
+  # buildAndRunBinary "test_process_attestation", "tests/spec_block_processing/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
+  # buildAndRunBinary "test_process_deposits", "tests/spec_block_processing/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
+  # buildAndRunBinary "all_fixtures_require_ssz", "tests/official/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
+  # buildAndRunBinary "test_attestation_pool", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
+  # buildAndRunBinary "test_block_pool", "tests/", """-d:chronicles_log_level=TRACE -d:const_preset=mainnet -d:BLS_FORCE_BACKEND=miracl -d:chronicles_sinks="json[file]""""
 
   # State and block sims; getting to 4th epoch triggers consensus checks
   buildAndRunBinary "state_sim", "research/", "-d:const_preset=mainnet -d:chronicles_log_level=INFO", "--validators=3000 --slots=128"
diff --git a/vendor/nim-blscurve b/vendor/nim-blscurve
index 3878b9bf3..b5a77f1d2 160000
--- a/vendor/nim-blscurve
+++ b/vendor/nim-blscurve
@@ -1 +1 @@
-Subproject commit 3878b9bf324fd895f07f2c3a07622fac7c939e21
+Subproject commit b5a77f1d29f6b5f6d5bf16853eea63d75072d0be