diff --git a/INSTALL.md b/INSTALL.md
index 979ea30ce6..66684a7ecb 100755
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -171,19 +171,13 @@ A library for finding and handling crystal symmetries
   * The spglib can be downloaded from https://github.com/atztogo/spglib
   * For building CP2K with the spglib add `-D__SPGLIB` to DFLAGS
 
-### 2q. JSON-Fortran (optional, required for SIRIUS)
-JSON-Fortran is a Fortran 2008 JSON API.
-  * The code is available at https://github.com/jacobwilliams/json-fortran
-  * For building CP2K with JSON-Fortran add `-D__JSON` to DFLAGS.
-
-### 2r. SIRIUS (optional, plane wave calculations)
+### 2q. SIRIUS (optional, plane wave calculations)
 SIRIUS is a domain specific library for electronic structure calculations.
   * The code is available at https://github.com/electronic-structure/SIRIUS
   * For building CP2K with SIRIUS add `-D__SIRIUS` to DFLAGS.
-  * Furthermore, SIRIUS depends on JSON-Fortran.
   * See https://electronic-structure.github.io/SIRIUS/ for more information.
 
-### 2s. FPGA (optional, plane wave FFT calculations)
+### 2r. FPGA (optional, plane wave FFT calculations)
   * Use `-D__PW_FPGA` to enable FPGA support for PW (fft) calculations. Currently tested only for Intel Stratix 10 and Arria 10 GX1150 FPGAs.
   * Supports single precision and double precision fft calculations with the use of dedicated APIs.
   * Double precision is the default API chosen when set using the `-D__PW_FPGA` flag.
diff --git a/src/cp2k_info.F b/src/cp2k_info.F
index f4414b7f50..6b10da682f 100644
--- a/src/cp2k_info.F
+++ b/src/cp2k_info.F
@@ -271,9 +271,6 @@ CONTAINS
 #if defined __MKL
       flags = TRIM(flags)//" mkl"
 #endif
-#if defined __JSON
-      flags = TRIM(flags)//" json"
-#endif
 #if defined __SIRIUS
       flags = TRIM(flags)//" sirius"
 #endif
diff --git a/tools/autotools/configure.ac b/tools/autotools/configure.ac
index 419a9b47b9..d3d9a2ff4e 100644
--- a/tools/autotools/configure.ac
+++ b/tools/autotools/configure.ac
@@ -207,13 +207,6 @@ dnl check for libvdwxc
 ACX_LIBVDWXC([options="$options libvdwxc"; LIBVDWXC_DFLAGS="-D__LIBVDWXC"], [])
 AC_SUBST(LIBVDWXC_DFLAGS)
 
-SECTION_TITLE([json fortran (SIRIUS dependency)])
-dnl check for libvdwxc
-ACX_JSON_FORTRAN([options="$options json-fortran"; JSON_FORTRAN_DFLAGS="-D__JSON"], [])
-AC_SUBST(JSON_FORTRAN_DFLAGS)
-
-
-
 SECTION_TITLE([ParMETIS, PTSCOTCH and SuperLU])
 dnl check for parmetis
 ACX_PARMETIS([options="$options ParMETIS"; PARMETIS_DFLAGS="-D__PARMETIS"], [])
diff --git a/tools/autotools/m4/ax_json_fortran.m4 b/tools/autotools/m4/ax_json_fortran.m4
deleted file mode 100644
index 5fd638318f..0000000000
--- a/tools/autotools/m4/ax_json_fortran.m4
+++ /dev/null
@@ -1,25 +0,0 @@
-# -*- Autoconf -*-
-AU_ALIAS([ACX_JSON_FORTRAN], [AX_JSON_FORTRAN])
-AC_DEFUN([ACX_JSON_FORTRAN],
-        [
-        _ac_have_json_fortran=no
-
-        AC_ARG_WITH(json-fortran,
-                    [AC_HELP_STRING([--with-json-fortran=yes/no/prefix],
-                                   ["use the json fortran library (SIRIUS dependency)"])],
-                    [json_fortran_prefix="$withval"],
-                    [json_fortran_prefix="/usr/local"])
-        pkg_config_path_save=$PKG_CONFIG_PATH
-        PKG_CONFIG_PATH=${json_fortran_prefix}/lib/pkgconfig:$PKG_CONFIG_PATH
-       AS_IF([test "$with_json_fortran" != "no"],
-             [PKG_CHECK_EXISTS([json-fortran], 
-                               [PKG_CHECK_MODULES([JSON_FORTRAN], [json-fortran], [_ac_have_json_fortran=yes], [AC_MSG_WARN([json-fortran not found])])], 
-                               [])
-             ])
-        PKG_CONFIG_PATH=$pkg_config_path_save 
-        AC_SUBST(JSON_FORTRAN_CFLAGS)
-        AC_SUBST(JSON_FORTRAN_LIBS)
-        AC_SUBST(JSON_FORTRAN_LDFLAGS)
-        AS_IF([test "_ac_have_json_fortran" == "yes"], [$1], [$2])
-])
-#
diff --git a/tools/toolchain/Dockerfile b/tools/toolchain/Dockerfile
index ff78db38ae..1ff4c78c3a 100644
--- a/tools/toolchain/Dockerfile
+++ b/tools/toolchain/Dockerfile
@@ -126,9 +126,6 @@ RUN ./scripts/install_libvdwxc.sh && rm -rf ./build
 COPY ./scripts/install_sirius.sh ./scripts/
 RUN ./scripts/install_sirius.sh && rm -rf ./build
 
-COPY ./scripts/install_json_fortran.sh ./scripts/
-RUN ./scripts/install_json_fortran.sh && rm -rf ./build
-
 COPY ./scripts/arch_base.tmpl \
      ./scripts/generate_arch_files.sh ./scripts/
 RUN ./scripts/generate_arch_files.sh && rm -rf ./build
diff --git a/tools/toolchain/install_cp2k_toolchain.sh b/tools/toolchain/install_cp2k_toolchain.sh
index 4043922459..613b188740 100755
--- a/tools/toolchain/install_cp2k_toolchain.sh
+++ b/tools/toolchain/install_cp2k_toolchain.sh
@@ -212,7 +212,7 @@ The --with-PKG options follow the rules:
   --with-quip             Enable interface to QUIP library
                           Default = no
   --with-sirius           Enable interface to the plane wave SIRIUS library.
-                          This package requires: gsl, libspg, elpa, scalapack, json-fortran, hdf5 and libxc.
+                          This package requires: gsl, libspg, elpa, scalapack, hdf5 and libxc.
                           Default = install
   --with-gsl              Enable the gnu scientific library
                           Default = install
@@ -223,10 +223,6 @@ The --with-PKG options follow the rules:
                           Default = install
   --with-hdf5             Enable the hdf5 library (used by the sirius library)
                           Default = install
-  --with-json-fortran     Enable the json fortran library (used by cp2k when sirius is activated)
-                          This package depends on cmake.
-                          Default = install
-
 
 FURTHER INSTRUCTIONS
 
@@ -263,7 +259,7 @@ tool_list="valgrind cmake gcc"
 mpi_list="mpich openmpi"
 math_list="mkl acml openblas reflapack"
 lib_list="fftw libint libxc libsmm libxsmm scalapack elpa \
-          ptscotch parmetis metis superlu pexsi quip gsl spglib hdf5 libvdwxc sirius json_fortran"
+          ptscotch parmetis metis superlu pexsi quip gsl spglib hdf5 libvdwxc sirius"
 package_list="$tool_list $mpi_list $math_list $lib_list"
 # ------------------------------------------------------------------------
 
@@ -304,7 +300,6 @@ with_sirius="__INSTALL__"
 with_gsl="__INSTALL__"
 with_spglib="__INSTALL__"
 with_hdf5="__INSTALL__"
-with_json_fortran="__INSTALL__"
 with_elpa="__INSTALL__"
 with_libvdwxc="__INSTALL__"
 
@@ -600,9 +595,6 @@ while [ $# -ge 1 ] ; do
         --with-hdf5*)
             with_hdf5=$(read_with $1)
             ;;
-        --with-json*)
-            with_json_fortran=$(read_with $1)
-            ;;
         --with-libvdwxc*)
             with_libvdwxc=$(read_with $1)
             ;;
@@ -741,11 +733,6 @@ if [ "$with_spglib" = "__INSTALL__" ] ; then
     [ "$with_cmake" = "__DONTUSE__" ] && with_cmake="__INSTALL__"
 fi
 
-# json-fortran requires cmake.
-if [ "$with_json_fortran" = "__INSTALL__" ] ; then
-    [ "$with_cmake" = "__DONTUSE__" ] && with_cmake="__INSTALL__"
-fi
-
 # SIRIUS dependencies. Remove the gsl library from the dependencies if SIRIUS is not activated
 if [ "$with_sirius" = "__INSTALL__" ] ; then
     if [ "$with_gsl" = "__DONTUSE__" ] ; then
@@ -768,10 +755,6 @@ if [ "$with_sirius" = "__INSTALL__" ] ; then
         report_error "For SIRIUS to work you need a working hdf5 library use --with-hdf5 option to specify if you wish to install the library or specify its location."
         exit 1
     fi
-    if [ "$with_json_fortran" = "__DONTUSE__"  ] ; then
-        report_error "For SIRIUS to work you need a working json-fortran library use --with-json option to specify if you wish to install it or specify its location."
-    exit 1
-    fi
 fi
 
 
@@ -945,7 +928,6 @@ else
     ./scripts/install_hdf5.sh
     ./scripts/install_libvdwxc.sh
     ./scripts/install_sirius.sh
-    ./scripts/install_json_fortran.sh
     ./scripts/generate_arch_files.sh
 fi
 
diff --git a/tools/toolchain/scripts/install_json_fortran.sh b/tools/toolchain/scripts/install_json_fortran.sh
deleted file mode 100755
index e3e73d6d1b..0000000000
--- a/tools/toolchain/scripts/install_json_fortran.sh
+++ /dev/null
@@ -1,91 +0,0 @@
-#!/bin/bash -e
-[ "${BASH_SOURCE[0]}" ] && SCRIPT_NAME="${BASH_SOURCE[0]}" || SCRIPT_NAME=$0
-SCRIPT_DIR="$(cd "$(dirname "$SCRIPT_NAME")" && pwd -P)"
-
-json_fortran_ver="7.0.0"
-json_fortran_sha256="9b5b6235489b27d572bbc7620ed8e039fa9d4d14d41b1581b279be9db499f32c"
-
-source "${SCRIPT_DIR}"/common_vars.sh
-source "${SCRIPT_DIR}"/tool_kit.sh
-source "${SCRIPT_DIR}"/signal_trap.sh
-source "${INSTALLDIR}"/toolchain.conf
-source "${INSTALLDIR}"/toolchain.env
-
-[ -f "${BUILDDIR}/setup_json_fortran" ] && rm -f "${BUILDDIR}/setup_json_fortran"
-
-! [ -d "${BUILDDIR}" ] && mkdir -p "${BUILDDIR}"
-cd "${BUILDDIR}"
-
-case "$with_json_fortran" in
-    __INSTALL__)
-        echo "==================== Installing json_fortran ===================="
-        pkg_install_dir="${INSTALLDIR}/json_fortran-${json_fortran_ver}"
-        install_lock_file="$pkg_install_dir/install_successful"
-        if verify_checksums "${install_lock_file}" ; then
-            echo "json-fortran-${json_fortran_ver} is already installed, skipping it."
-        else
-            if [ -f json-fortran-${json_fortran_ver}.tar.gz ] ; then
-                echo "json-fortran-${json_fortran_ver}.tar.gz is found"
-            else
-                download_pkg ${DOWNLOADER_FLAGS} ${json_fortran_sha256} \
-                             https://github.com/jacobwilliams/json-fortran/archive/${json_fortran_ver}.tar.gz \
-                             -o json-fortran-${json_fortran_ver}.tar.gz
-            fi
-            echo "Installing from scratch into ${pkg_install_dir}"
-            [ -d json-fortran-${json_fortran_ver} ] && rm -rf json-fortran-${json_fortran_ver}
-            tar -xzf json-fortran-${json_fortran_ver}.tar.gz
-            cd json-fortran-${json_fortran_ver}
-            mkdir build
-            cd build
-            cmake -DCMAKE_INSTALL_PREFIX="${pkg_install_dir}" -DUSE_GNU_INSTALL_CONVENTION=on -DSKIP_DOC_GEN=true -DCMAKE_INSTALL_LIBDIR=lib .. > make.log 2>&1
-            make -j $NPROCS >> make.log 2>&1
-            make -j $NPROCS install > install.log 2>&1
-            cd ../..
-            write_checksums "${install_lock_file}" "${SCRIPT_DIR}/$(basename ${SCRIPT_NAME})"
-        fi
-
-        JSON_CFLAGS="-I'${pkg_install_dir}/include'"
-        JSON_LDFLAGS="-L'${pkg_install_dir}/lib' -Wl,-rpath='${pkg_install_dir}/lib'"
-        ;;
-    __SYSTEM__)
-        echo "==================== Finding json-fortran from system paths ===================="
-        add_include_from_paths JSON_CFLAGS "json_file_module.mod" $INCLUDE_PATHS
-        add_lib_from_paths JSON_LDFLAGS "libjsonfortran.*" $LIB_PATHS
-        ;;
-    __DONTUSE__)
-        ;;
-    *)
-        echo "==================== Linking json-fortran to user paths ===================="
-        pkg_install_dir="$with_json"
-        check_dir "$pkg_install_dir/lib"
-        check_dir "$pkg_install_dir/lib64"
-        check_dir "$pkg_install_dir/include"
-        JSON_CFLAGS="-I'${pkg_install_dir}/include'"
-        JSON_LDFLAGS="-L'${pkg_install_dir}/lib' -Wl,-rpath='${pkg_install_dir}/lib'"
-        ;;
-esac
-if [ "$with_json_fortran" != "__DONTUSE__" ] ; then
-    JSON_LIBS="-ljsonfortran"
-    if [ "$with_json_fortran" != "__SYSTEM__" ] ; then
-        cat << EOF > "${BUILDDIR}/setup_json_fortran"
-prepend_path LD_LIBRARY_PATH "$pkg_install_dir/lib"
-prepend_path LD_RUN_PATH "$pkg_install_dir/lib"
-prepend_path LIBRARY_PATH "$pkg_install_dir/lib"
-prepend_path CPATH "$pkg_install_dir/include"
-export JSON_CFLAGS="${JSON_CFLAGS}"
-export JSON_LDFLAGS="${JSON_LDFLAGS}"
-export CP_DFLAGS="\${CP_DFLAGS} -D__JSON"
-export CP_CFLAGS="\${CP_CFLAGS} ${JSON_CFLAGS}"
-export CP_LDFLAGS="\${CP_LDFLAGS} ${JSON_LDFLAGS}"
-export CP_LIBS="${JSON_LIBS} \${CP_LIBS}"
-EOF
-        cat "${BUILDDIR}/setup_json_fortran" >> $SETUPFILE
-    fi
-fi
-
-# update toolchain environment
-load "${BUILDDIR}/setup_json_fortran"
-export -p > "${INSTALLDIR}/toolchain.env"
-
-cd "${ROOTDIR}"
-report_timing "json-fortran"