diff --git a/.github/actions/fedora-s390x/Dockerfile b/.github/actions/fedora-s390x/Dockerfile
new file mode 100644
index 000000000..b2a0030e1
--- /dev/null
+++ b/.github/actions/fedora-s390x/Dockerfile
@@ -0,0 +1,8 @@
+FROM --platform=linux/s390x multiarch/fedora:29-s390x
+
+COPY entry.sh /entry.sh
+
+RUN sh -c 'curl https://dl.google.com/go/go1.14.4.linux-s390x.tar.gz | tar xz -C /usr/local'
+RUN ln -s /usr/local/go/bin/go /usr/local/bin/go
+
+ENTRYPOINT ["sh", "/entry.sh"]
diff --git a/.github/actions/fedora-s390x/action.yml b/.github/actions/fedora-s390x/action.yml
new file mode 100644
index 000000000..43f5d8218
--- /dev/null
+++ b/.github/actions/fedora-s390x/action.yml
@@ -0,0 +1,7 @@
+---
+name: 'fedora-s390x'
+description: 'builds golang inside linux/s390x'
+
+runs:
+  using: 'docker'
+  image: 'Dockerfile'
diff --git a/.github/actions/fedora-s390x/entry.sh b/.github/actions/fedora-s390x/entry.sh
new file mode 100755
index 000000000..dcd6f306c
--- /dev/null
+++ b/.github/actions/fedora-s390x/entry.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+
+sh -c "echo $*"
+echo "Hello"
+date
+pwd
+ls
+uname -a
+GODEBUG=asyncpreemptoff=1 go test -v ./math/...
+date
diff --git a/.github/workflows/ci-actions.yml b/.github/workflows/ci-actions.yml
index b7f390df4..a8bdcef83 100644
--- a/.github/workflows/ci-actions.yml
+++ b/.github/workflows/ci-actions.yml
@@ -1,3 +1,4 @@
+---
 name: CIRCL
 on:
   push:
@@ -9,6 +10,7 @@ on:
 jobs:
   amd64_job:
     name: Go-${{matrix.GOVER}}/amd64
+    if: 1==0
     runs-on: ubuntu-18.04
     strategy:
       matrix:
@@ -33,28 +35,24 @@ jobs:
         run: go build -v ./...
       - name: Testing
         run: go test -v ./...
-  exotic_job:
-    name: Go-${{matrix.CFG[2]}}/${{matrix.CFG[0]}}
+  s390x_job:
+    name: Go-1.14/s390x
     runs-on: ubuntu-18.04
-    strategy:
-      matrix:
-        CFG: [ [arm64,arm64v8,1.14] ]
     steps:
       - uses: actions/checkout@v2
       - name: Enabling Docker Experimental
         run: |
-          echo $'{\n    "experimental": true\n}' | sudo tee /etc/docker/daemon.json
+          echo $'{\n\t"experimental": true\n}' | sudo tee /etc/docker/daemon.json
           sudo service docker restart
       - name: Pulling Images
         run: |
           docker pull -q multiarch/qemu-user-static
-          docker pull -q --platform linux/${{matrix.CFG[0]}} ${{matrix.CFG[1]}}/golang:${{matrix.CFG[2]}}
+          docker pull -q multiarch/fedora:29-s390x
           docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
       - name: Testing
-        run: |
-          docker run --rm -v `pwd`:`pwd` -w `pwd` ${{matrix.CFG[1]}}/golang:${{matrix.CFG[2]}} go test -v ./...
+        uses: ./.github/actions/fedora-s390x
   coverage_amd64_job:
-    needs: [ amd64_job ]
+    needs: [amd64_job]
     if: github.event_name == 'push'
     runs-on: ubuntu-18.04
     name: amd64/coverage
diff --git a/dh/csidh/fp511_amd64.go b/dh/csidh/fp511_amd64.go
index bdc5b103b..495c6e3fd 100644
--- a/dh/csidh/fp511_amd64.go
+++ b/dh/csidh/fp511_amd64.go
@@ -1,4 +1,4 @@
-// +build amd64,!noasm
+// +build amd64
 
 package csidh
 
@@ -11,12 +11,9 @@ import (
 var (
 	// Signals support for BMI2 (MULX)
 	hasBMI2 = cpu.X86.HasBMI2
-	// Signals support for ADX and BMI2
-	hasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
+	_       = hasBMI2
 )
 
-var _ = hasBMI2
-
 func mul512(r, m1 *fp, m2 uint64)     { mul512Amd64(r, m1, m2) }
 func cswap512(x, y *fp, choice uint8) { cswap512Amd64(x, y, choice) }
 func mulRdc(r, x, y *fp)              { mulRdcAmd64(r, x, y) }
@@ -36,7 +33,7 @@ func mulRdcAmd64(r, x, y *fp) {
 	var t fp
 	var c uint64
 
-	if hasADXandBMI2 {
+	if cpu.X86.HasBMI2 && cpu.X86.HasADX {
 		mulBmiAsm(r, x, y)
 	} else {
 		mulGeneric(r, x, y)
diff --git a/dh/sidh/internal/p434/arith_amd64.go b/dh/sidh/internal/p434/arith_amd64.go
new file mode 100644
index 000000000..302f7fc83
--- /dev/null
+++ b/dh/sidh/internal/p434/arith_amd64.go
@@ -0,0 +1,6 @@
+package p434
+
+import "golang.org/x/sys/cpu"
+
+// HasADXandBMI2 signals support for ADX and BMI2
+var HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
diff --git a/dh/sidh/internal/p434/params.go b/dh/sidh/internal/p434/params.go
index bf6261cb8..53337a20a 100644
--- a/dh/sidh/internal/p434/params.go
+++ b/dh/sidh/internal/p434/params.go
@@ -4,7 +4,6 @@ package p434
 
 import (
 	"github.com/cloudflare/circl/dh/sidh/internal/common"
-	"golang.org/x/sys/cpu"
 )
 
 const (
@@ -13,9 +12,6 @@ const (
 )
 
 var (
-	// HasADXandBMI2 signals support for ADX and BMI2
-	HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
-
 	// P434 is a prime used by field Fp434
 	P434 = common.Fp{
 		0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF, 0xFDC1767AE2FFFFFF,
diff --git a/dh/sidh/internal/p503/arith_amd64.go b/dh/sidh/internal/p503/arith_amd64.go
new file mode 100644
index 000000000..a4101ee6e
--- /dev/null
+++ b/dh/sidh/internal/p503/arith_amd64.go
@@ -0,0 +1,13 @@
+package p503
+
+import "golang.org/x/sys/cpu"
+
+// According to https://github.com/golang/go/issues/28230,
+// variables referred from the assembly must be in the same package.
+var (
+	// HasBMI2 signals support for MULX which is in BMI2
+	HasBMI2 = cpu.X86.HasBMI2
+
+	// HasADXandBMI2 signals support for ADX and BMI2
+	HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
+)
diff --git a/dh/sidh/internal/p503/params.go b/dh/sidh/internal/p503/params.go
index 5bf811d6b..f19049678 100644
--- a/dh/sidh/internal/p503/params.go
+++ b/dh/sidh/internal/p503/params.go
@@ -4,7 +4,6 @@ package p503
 
 import (
 	"github.com/cloudflare/circl/dh/sidh/internal/common"
-	"golang.org/x/sys/cpu"
 )
 
 const (
@@ -14,13 +13,6 @@ const (
 
 // P503 is a prime used by field Fp503
 var (
-	// According to https://github.com/golang/go/issues/28230,
-	// variables referred from the assembly must be in the same package.
-	// HasBMI2 signals support for MULX which is in BMI2
-	HasBMI2 = cpu.X86.HasBMI2
-	// HasADXandBMI2 signals support for ADX and BMI2
-	HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
-
 	// P503 is a prime used by field Fp503
 	P503 = common.Fp{
 		0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF, 0xABFFFFFFFFFFFFFF,
diff --git a/dh/sidh/internal/p751/arith_amd64.go b/dh/sidh/internal/p751/arith_amd64.go
new file mode 100644
index 000000000..83ca176a6
--- /dev/null
+++ b/dh/sidh/internal/p751/arith_amd64.go
@@ -0,0 +1,10 @@
+package p751
+
+import "golang.org/x/sys/cpu"
+
+var (
+	// HasBMI2 signals support for MULX which is in BMI2
+	HasBMI2 = cpu.X86.HasBMI2
+	// HasADXandBMI2 signals support for ADX and BMI2
+	HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
+)
diff --git a/dh/sidh/internal/p751/params.go b/dh/sidh/internal/p751/params.go
index 65d6c5ba0..139918df3 100644
--- a/dh/sidh/internal/p751/params.go
+++ b/dh/sidh/internal/p751/params.go
@@ -4,7 +4,6 @@ package p751
 
 import (
 	"github.com/cloudflare/circl/dh/sidh/internal/common"
-	"golang.org/x/sys/cpu"
 )
 
 const (
@@ -13,10 +12,6 @@ const (
 )
 
 var (
-	// HasBMI2 signals support for MULX which is in BMI2
-	HasBMI2 = cpu.X86.HasBMI2
-	// HasADXandBMI2 signals support for ADX and BMI2
-	HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
 	// P751 is a prime used by field Fp751
 	P751 = common.Fp{
 		0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff,
diff --git a/sign/dilithium/internal/common/amd64.go b/sign/dilithium/internal/common/util_amd64.go
similarity index 100%
rename from sign/dilithium/internal/common/amd64.go
rename to sign/dilithium/internal/common/util_amd64.go
diff --git a/sign/dilithium/internal/common/amd64.s b/sign/dilithium/internal/common/util_amd64.s
similarity index 100%
rename from sign/dilithium/internal/common/amd64.s
rename to sign/dilithium/internal/common/util_amd64.s