diff --git a/appredict-chaste-libs/Dockerfile b/appredict-chaste-libs/Dockerfile
index 41bfca1..c419349 100644
--- a/appredict-chaste-libs/Dockerfile
+++ b/appredict-chaste-libs/Dockerfile
@@ -1,13 +1,13 @@
-FROM debian:buster-slim
+FROM debian:bullseye-slim
 
 USER root
 
-RUN echo "deb http://deb.debian.org/debian buster main contrib non-free" >> /etc/apt/sources.list
+RUN echo "deb http://deb.debian.org/debian bullseye main contrib non-free" >> /etc/apt/sources.list
 
 # Install dependencies with recommended, applicable suggested and other useful packages
 RUN apt-get update && \
-    apt-get install -y g++ cmake && \ 
-    apt-get install -y --no-install-recommends \ 
+    apt-get install -y g++ cmake && \
+    apt-get install -y --no-install-recommends \
     wget \
     git \
     petsc-dev \
@@ -26,4 +26,4 @@ RUN apt-get update && \
 
 ENV HOME=/home/appredict
 RUN useradd -ms /bin/bash -d $HOME appredict
-USER appredict
\ No newline at end of file
+USER appredict
diff --git a/appredict-no-emulators/Dockerfile b/appredict-no-emulators/Dockerfile
index 3b25901..0f943e5 100644
--- a/appredict-no-emulators/Dockerfile
+++ b/appredict-no-emulators/Dockerfile
@@ -37,7 +37,7 @@ RUN find . ! -name shannon_wang_puglisi_weber_bers_2004.cellml ! -name ten_tussc
 
 RUN mkdir -p ${dir_build}
 WORKDIR ${dir_build}
-RUN cmake -j ${build_processors} \
+RUN cmake \
     -DCMAKE_BUILD_TYPE=Release \
     -DChaste_ERROR_ON_WARNING=OFF \
     -DChaste_UPDATE_PROVENANCE=ON \