diff --git a/boring-nginx/Dockerfile b/boring-nginx/Dockerfile
index aef341d..b1f90e6 100644
--- a/boring-nginx/Dockerfile
+++ b/boring-nginx/Dockerfile
@@ -45,9 +45,9 @@ RUN echo "@commuedge https://nl.alpinelinux.org/alpine/edge/community" >> /etc/a
  && sed -n 's/\$addx = 0/\$addx = 1/p' crypto/*/asm/*.pl \
  && sed -n 's/\$avx = 1/\$avx = 2/p' crypto/*/asm/*.pl \
  && sed -n 's/\$shaext=0/\$shaext=1/p' crypto/*/asm/*.pl \
- && sed -i '' 's@\$shaext[ ]*=[ ]*0;@\$shaext = 1;@' crypto/*/asm/*.pl \
- && sed -i '' 's@\$avx[ ]*=[ ]*[0|1];@\$avx = 2;@' crypto/*/asm/*.pl \
- && sed -i '' 's@\$addx[ ]*=[ ]*0;@\$addx = 1;@' crypto/*/asm/*.pl \
+ && sed -i 's@\$shaext[ ]*=[ ]*0;@\$shaext = 1;@' crypto/*/asm/*.pl \
+ && sed -i 's@\$avx[ ]*=[ ]*[0|1];@\$avx = 2;@' crypto/*/asm/*.pl \
+ && sed -i 's@\$addx[ ]*=[ ]*0;@\$addx = 1;@' crypto/*/asm/*.pl \
  && mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release .. \
  && make -j ${NB_CORES} && cd .. \
  && mkdir -p .openssl/lib/ && cd .openssl && ln -s ../include && cd .. \