diff --git a/Docker/ubuntu2004-cpu/Dockerfile b/Docker/ubuntu2004-cpu/Dockerfile
index 500ed35..ba99634 100644
--- a/Docker/ubuntu2004-cpu/Dockerfile
+++ b/Docker/ubuntu2004-cpu/Dockerfile
@@ -23,8 +23,8 @@ RUN git clone --depth 1 --branch master \
      mkdir build-ubuntu && cd build-ubuntu && \
      cmake -DCMAKE_INSTALL_PREFIX=/opt/sagecal \
      -DBLA_VENDOR=OpenBLAS \
-     -DCMAKE_CXX_FLAGS="-O3 -fopenmp -ffast-math -lmvec -lm" \
-     -DCMAKE_C_FLAGS="-O3 -fopenmp -ffast-math -lmvec -lm" .. && \
+     -DCMAKE_CXX_FLAGS="-O3 -ffast-math -lmvec -lm" \
+     -DCMAKE_C_FLAGS="-O3 -ffast-math -lmvec -lm" .. && \
      make -j4 && \
      make install
 RUN ls -alsrt /opt/sagecal && \
diff --git a/Docker/ubuntu2004-cuda/Dockerfile b/Docker/ubuntu2004-cuda/Dockerfile
index da57aaa..a0e28ab 100644
--- a/Docker/ubuntu2004-cuda/Dockerfile
+++ b/Docker/ubuntu2004-cuda/Dockerfile
@@ -33,8 +33,8 @@ RUN git clone --depth 1 --branch master \
      -DHAVE_CUDA=ON -DCUDA_NVCC_FLAGS="-gencode arch=compute_75,code=sm_75 -O3" \
      -DNUM_GPU=2 -DBLA_VENDOR=OpenBLAS \
      -DCMAKE_CXX_COMPILER=g++-8 -DCMAKE_C_COMPILER=gcc-8 \
-     -DCMAKE_CXX_FLAGS="-O3 -fopenmp -ffast-math -lmvec -lm" \
-     -DCMAKE_C_FLAGS="-O3 -fopenmp -ffast-math -lmvec -lm" .. && \
+     -DCMAKE_CXX_FLAGS="-O3 -ffast-math -lmvec -lm" \
+     -DCMAKE_C_FLAGS="-O3 -ffast-math -lmvec -lm" .. && \
      make -j4 && \
      make install
 RUN ls -alsrt /opt/sagecal && \
diff --git a/INSTALL.md b/INSTALL.md
index 1ee3eb9..6c49d13 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -26,8 +26,8 @@ The option *-DBLA_VENDOR=OpenBLAS* is to select OpenBLAS explicitly, but other B
 To only build *libdirac* (shared) library, use *-DLIB_ONLY=1* option (also *-DBLA_VENDOR* to select the BLAS flavour). This library can be used with pkg-config using *lib/pkgconfig/libdirac.pc*. To build *libdirac* with GPU support, use *-DHAVE_CUDA=ON* with *-DLIB_ONLY=1* and give *-fPIC* compiler flag (for both *-DCMAKE_CXX_FLAGS* and *-DCMAKE_C_FLAGS*). With GPU support, only a static library is built because it needs to match the GPU architecture.
 
 ### Vectorized math operations
-SAGECal can use ***libmvec*** vectorized math operations, both in GPU and CPU versions. In order to enable this, use compiler options *-fopenmp -ffast-math -lmvec -lm* for both gcc and g++. Also *-mavx*, *-mavx2* etc. can be added. Here is an example for CPU version
+SAGECal can use ***libmvec*** vectorized math operations, both in GPU and CPU versions. In order to enable this, use compiler options *-ffast-math -lmvec -lm* for both gcc and g++. Also *-mavx*, *-mavx2* etc. can be added. Here is an example for CPU version
 
 ```
-cmake ..  -DCMAKE_CXX_FLAGS='-g -O3 -Wall -fopenmp -ffast-math -lmvec -lm -mavx2' -DCMAKE_C_FLAGS='-g -O3 -Wall -ffast-math -lmvec -lm -mavx2' 
+cmake ..  -DCMAKE_CXX_FLAGS='-g -O3 -Wall -ffast-math -lmvec -lm -mavx2' -DCMAKE_C_FLAGS='-g -O3 -Wall -ffast-math -lmvec -lm -mavx2' 
 ```