diff --git a/bout-next-sundials-ubuntu.dkr b/bout-next-sundials-ubuntu.dkr
index 8a3959e..3c22b8d 100644
--- a/bout-next-sundials-ubuntu.dkr
+++ b/bout-next-sundials-ubuntu.dkr
@@ -72,8 +72,8 @@ RUN useradd -ms /bin/bash boutuser \
 USER boutuser
 WORKDIR /home/boutuser
 
-#RUN git clone -b next --depth 1 git://github.com/boutproject/BOUT-dev.git BOUT-next \
-RUN git clone -b sundials-extra-libs --depth 1 git://github.com/boutproject/BOUT-dev.git BOUT-next \
+#RUN git clone -b next --depth 1 https://github.com/boutproject/BOUT-dev.git BOUT-next \
+RUN git clone -b sundials-extra-libs --depth 1 https://github.com/boutproject/BOUT-dev.git BOUT-next \
  && chown boutuser /home/boutuser/BOUT-next
 
 WORKDIR /home/boutuser/BOUT-next
diff --git a/bout-next.dkr b/bout-next.dkr
index 7b96823..d323870 100644
--- a/bout-next.dkr
+++ b/bout-next.dkr
@@ -150,7 +150,7 @@ RUN useradd -ms /bin/bash boutuser \
 USER boutuser
 WORKDIR /home/boutuser
 
-RUN git clone -b next --depth 1 git://github.com/boutproject/BOUT-dev.git BOUT-next \
+RUN git clone -b next --depth 1 https://github.com/boutproject/BOUT-dev.git BOUT-next \
  && chown boutuser /home/boutuser/BOUT-next
 
 WORKDIR /home/boutuser/BOUT-next
diff --git a/bout.dkr b/bout.dkr
index 1b015d5..c34cfb2 100644
--- a/bout.dkr
+++ b/bout.dkr
@@ -143,7 +143,7 @@ RUN python3 -m pip install cython ipython
 # Build and install BOUT++
 # ----------------------------------------------------------------
 WORKDIR /opt
-RUN git clone -b v4.2.2 --depth 1 git://github.com/boutproject/BOUT-dev.git BOUT-dev
+RUN git clone -b v4.2.2 --depth 1 https://github.com/boutproject/BOUT-dev.git BOUT-dev
 
 WORKDIR /opt/BOUT-dev
 RUN ./configure --with-petsc PETSC_DIR=/petsc-3.9.3 PETSC_ARCH=arch-linux2-cxx-debug --with-sundials=/usr/ --with-fftw --with-netcdf --enable-openmp --with-cvode --with-arkode --with-slepc --with-lapack LIBS="-llapack -lblas" --localedir=$PWD/locale --enable-shared \