diff --git a/docker/Dockerfile.aarch64-linux-android b/docker/Dockerfile.aarch64-linux-android
index 0025dfb1f..3a2d9025a 100644
--- a/docker/Dockerfile.aarch64-linux-android
+++ b/docker/Dockerfile.aarch64-linux-android
@@ -14,7 +14,7 @@ COPY android-system.sh /
 RUN /android-system.sh arm64
 
 COPY qemu.sh /
-RUN /qemu.sh aarch64 android
+RUN /qemu.sh aarch64
 
 RUN cp /android-ndk/sysroot/usr/lib/libz.so /system/lib/
 
diff --git a/docker/Dockerfile.aarch64-unknown-linux-gnu b/docker/Dockerfile.aarch64-unknown-linux-gnu
index 4fa959742..0f0703e3f 100644
--- a/docker/Dockerfile.aarch64-unknown-linux-gnu
+++ b/docker/Dockerfile.aarch64-unknown-linux-gnu
@@ -15,7 +15,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-arm64-cross
 
 COPY qemu.sh /
-RUN /qemu.sh aarch64 linux softmmu
+RUN /qemu.sh aarch64 softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.arm-linux-androideabi b/docker/Dockerfile.arm-linux-androideabi
index 38439fe68..16cd3a712 100644
--- a/docker/Dockerfile.arm-linux-androideabi
+++ b/docker/Dockerfile.arm-linux-androideabi
@@ -14,7 +14,7 @@ COPY android-system.sh /
 RUN /android-system.sh arm
 
 COPY qemu.sh /
-RUN /qemu.sh arm android
+RUN /qemu.sh arm
 
 RUN cp /android-ndk/sysroot/usr/lib/libz.so /system/lib/
 
diff --git a/docker/Dockerfile.armv7-linux-androideabi b/docker/Dockerfile.armv7-linux-androideabi
index 3eac0b7b3..11ffd5882 100644
--- a/docker/Dockerfile.armv7-linux-androideabi
+++ b/docker/Dockerfile.armv7-linux-androideabi
@@ -14,7 +14,7 @@ COPY android-system.sh /
 RUN /android-system.sh arm
 
 COPY qemu.sh /
-RUN /qemu.sh arm android
+RUN /qemu.sh arm
 
 RUN cp /android-ndk/sysroot/usr/lib/libz.so /system/lib/
 
diff --git a/docker/Dockerfile.armv7-unknown-linux-gnueabihf b/docker/Dockerfile.armv7-unknown-linux-gnueabihf
index 5ec9986d9..080a11eaf 100644
--- a/docker/Dockerfile.armv7-unknown-linux-gnueabihf
+++ b/docker/Dockerfile.armv7-unknown-linux-gnueabihf
@@ -15,7 +15,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-armhf-cross
 
 COPY qemu.sh /
-RUN /qemu.sh arm linux softmmu
+RUN /qemu.sh arm softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.i686-linux-android b/docker/Dockerfile.i686-linux-android
index b720060a8..fa3cdefe8 100644
--- a/docker/Dockerfile.i686-linux-android
+++ b/docker/Dockerfile.i686-linux-android
@@ -21,7 +21,7 @@ RUN /android-system.sh x86
 #
 # Running with qemu works as expected
 COPY qemu.sh /
-RUN /qemu.sh i386 android
+RUN /qemu.sh i386
 
 RUN cp /android-ndk/sysroot/usr/lib/libz.so /system/lib/
 
diff --git a/docker/Dockerfile.i686-unknown-linux-gnu b/docker/Dockerfile.i686-unknown-linux-gnu
index 6957d7f55..babb43721 100644
--- a/docker/Dockerfile.i686-unknown-linux-gnu
+++ b/docker/Dockerfile.i686-unknown-linux-gnu
@@ -14,7 +14,7 @@ RUN apt-get install -y --no-install-recommends \
     g++-multilib
 
 COPY qemu.sh /
-RUN /qemu.sh i386 linux softmmu
+RUN /qemu.sh i386 softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.mips-unknown-linux-gnu b/docker/Dockerfile.mips-unknown-linux-gnu
index e205a3a2b..0419ae202 100644
--- a/docker/Dockerfile.mips-unknown-linux-gnu
+++ b/docker/Dockerfile.mips-unknown-linux-gnu
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-mips-cross
 
 COPY qemu.sh /
-RUN /qemu.sh mips linux softmmu
+RUN /qemu.sh mips softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.mips64el-unknown-linux-gnuabi64 b/docker/Dockerfile.mips64el-unknown-linux-gnuabi64
index 69e935e9e..a94311451 100644
--- a/docker/Dockerfile.mips64el-unknown-linux-gnuabi64
+++ b/docker/Dockerfile.mips64el-unknown-linux-gnuabi64
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-mips64el-cross
 
 COPY qemu.sh /
-RUN /qemu.sh mips64el linux softmmu
+RUN /qemu.sh mips64el softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.mipsel-unknown-linux-gnu b/docker/Dockerfile.mipsel-unknown-linux-gnu
index 8f6a1e89d..941df0eb6 100644
--- a/docker/Dockerfile.mipsel-unknown-linux-gnu
+++ b/docker/Dockerfile.mipsel-unknown-linux-gnu
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-mipsel-cross
 
 COPY qemu.sh /
-RUN /qemu.sh mipsel linux softmmu
+RUN /qemu.sh mipsel softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.powerpc-unknown-linux-gnu b/docker/Dockerfile.powerpc-unknown-linux-gnu
index d99d72555..d8fad1fb0 100644
--- a/docker/Dockerfile.powerpc-unknown-linux-gnu
+++ b/docker/Dockerfile.powerpc-unknown-linux-gnu
@@ -15,7 +15,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-powerpc-cross
 
 COPY qemu.sh /
-RUN /qemu.sh ppc linux softmmu
+RUN /qemu.sh ppc softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.powerpc64-unknown-linux-gnu b/docker/Dockerfile.powerpc64-unknown-linux-gnu
index 9bd6b1957..babf3bf7d 100644
--- a/docker/Dockerfile.powerpc64-unknown-linux-gnu
+++ b/docker/Dockerfile.powerpc64-unknown-linux-gnu
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-ppc64-cross
 
 COPY qemu.sh /
-RUN /qemu.sh ppc64 linux softmmu
+RUN /qemu.sh ppc64 softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.powerpc64le-unknown-linux-gnu b/docker/Dockerfile.powerpc64le-unknown-linux-gnu
index 47d8f88b1..a209f92e8 100644
--- a/docker/Dockerfile.powerpc64le-unknown-linux-gnu
+++ b/docker/Dockerfile.powerpc64le-unknown-linux-gnu
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-ppc64el-cross
 
 COPY qemu.sh /
-RUN /qemu.sh ppc64le linux softmmu
+RUN /qemu.sh ppc64le softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.s390x-unknown-linux-gnu b/docker/Dockerfile.s390x-unknown-linux-gnu
index a087f2903..122d79d32 100644
--- a/docker/Dockerfile.s390x-unknown-linux-gnu
+++ b/docker/Dockerfile.s390x-unknown-linux-gnu
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-s390x-cross
 
 COPY qemu.sh /
-RUN /qemu.sh s390x linux softmmu
+RUN /qemu.sh s390x softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.sparc64-unknown-linux-gnu b/docker/Dockerfile.sparc64-unknown-linux-gnu
index 8a957dde6..bf89c936b 100644
--- a/docker/Dockerfile.sparc64-unknown-linux-gnu
+++ b/docker/Dockerfile.sparc64-unknown-linux-gnu
@@ -11,7 +11,7 @@ RUN apt-get install -y --no-install-recommends \
     libc6-dev-sparc64-cross
 
 COPY qemu.sh /
-RUN /qemu.sh sparc64 linux softmmu
+RUN /qemu.sh sparc64 softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/Dockerfile.x86_64-linux-android b/docker/Dockerfile.x86_64-linux-android
index 919b7ae80..be961ccc4 100644
--- a/docker/Dockerfile.x86_64-linux-android
+++ b/docker/Dockerfile.x86_64-linux-android
@@ -15,7 +15,7 @@ RUN /android-system.sh x86_64
 
 # Using qemu allows older host cpus (without sse4) to execute the target binaries
 COPY qemu.sh /
-RUN /qemu.sh x86_64 android
+RUN /qemu.sh x86_64
 
 RUN cp /android-ndk/sysroot/usr/lib/libz.so /system/lib/
 
diff --git a/docker/Dockerfile.x86_64-unknown-linux-gnu b/docker/Dockerfile.x86_64-unknown-linux-gnu
index 5c9a7174d..85b1bc021 100644
--- a/docker/Dockerfile.x86_64-unknown-linux-gnu
+++ b/docker/Dockerfile.x86_64-unknown-linux-gnu
@@ -15,7 +15,7 @@ RUN apt-get install -y --no-install-recommends \
     zlib1g-dev
 
 COPY qemu.sh /
-RUN /qemu.sh x86_64 linux softmmu
+RUN /qemu.sh x86_64 softmmu
 
 COPY dropbear.sh /
 RUN /dropbear.sh
diff --git a/docker/qemu.sh b/docker/qemu.sh
index 30a179191..69f3dac5d 100755
--- a/docker/qemu.sh
+++ b/docker/qemu.sh
@@ -16,8 +16,7 @@ main() {
     fi
 
     local arch=$1 \
-          os=$2 \
-          softmmu=$3 \
+          softmmu=${2:-} \
           td=$(mktemp -d)
 
     local dependencies=(