diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6bb8df7..4d00a38 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,7 +39,7 @@ jobs:
           key: ${{ runner.os }}-otp-${{ matrix.otp }}
       - name: Build submodules
         run: |
-          bash -c "echo 4.19.5 > lib/gpb/gpb.vsn"
+          bash -c "echo 4.19.8 > lib/gpb/gpb.vsn"
           git submodule foreach make
       - name: Install Z3
         run: bash -x fetch_z3.sh
@@ -53,7 +53,7 @@ jobs:
       - name: Build CutEr
         run: |
           autoconf
-          ./configure --with-protoc=$PWD/lib/protoc-3.20.2/bin/protoc
+          ./configure --with-protoc=$PWD/lib/protoc-22.0/bin/protoc
           make depend
           make -j 2
       - name: Run Dialyzer
diff --git a/README.md b/README.md
index a8cd8cd..4245d7f 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ This is the source tree for CutEr, a concolic unit testing tool for Erlang.
 License
 -------
 
-Copyright 2014-2022 by Aggelos Giantsios, Nikolaos Papaspyrou and Kostis Sagonas.
+Copyright 2014-2025 by Aggelos Giantsios, Nikolaos Papaspyrou and Kostis Sagonas.
 
 This program is distributed under the GPL, version 3 or later. Please see the COPYING file for details.
 
@@ -77,7 +77,7 @@ In order to use CutEr, you need the following programs:
 
   If you have a Linux or an OSX system then you can skip this step and, after you have downloaded or cloned this repository, you can run the provided `fetch_protoc.sh` script and follow the instructions.
 
-  If you are running on some other OS, download the [3.20.2 version](https://github.com/google/protobuf/releases/tag/v3.20.2) of **protoc** for your OS
+  If you are running on some other OS, download the [22.0 version](https://github.com/google/protobuf/releases/tag/v22.0) of **protoc** for your OS
   and follow the instructions in *readme.txt*.
 
 Installation
@@ -108,7 +108,7 @@ Installation
    then you need to specify the path of *protoc* to the configure script using a
    command like the following:
 
-        ./configure --with-protoc=$PWD/lib/protoc-3.20.2/bin/protoc
+        ./configure --with-protoc=$PWD/lib/protoc-22.0/bin/protoc
 
 * **[Optional]** You can run the unit and functional tests with `make test`
 
diff --git a/configure.ac b/configure.ac
index 3ea7e32..3f86aab 100644
--- a/configure.ac
+++ b/configure.ac
@@ -167,7 +167,7 @@ fi
 rm -f person.proto
 
 if test "$HAS_PROTOC" = "0"; then
-  AC_MSG_ERROR([protoc is missing. Please download version 3.11.0 of the package at https://github.com/google/protobuf/releases/tag/v3.11.0 and follow the instructions in the README. If you have a linux installation, then you can run ./fetch_protoc.sh and follow the instructions.])
+  AC_MSG_ERROR([protoc is missing. Please download version 22.0 of the package at https://github.com/google/protobuf/releases/tag/v22.0 and follow the instructions in the README. If you have a linux installation, then you can run ./fetch_protoc.sh and follow the instructions.])
 fi
 
 ###############################################
diff --git a/fetch_protoc.sh b/fetch_protoc.sh
index 972452d..3cf38b1 100755
--- a/fetch_protoc.sh
+++ b/fetch_protoc.sh
@@ -3,7 +3,7 @@
 set -e
 
 DL="lib"
-VER="3.20.2"
+VER="22.0"
 PROTOC_DIR="$DL/protoc-$VER"
 rm -rf $PROTOC_DIR
 
diff --git a/lib/gpb b/lib/gpb
index ed2c545..7b6fec1 160000
--- a/lib/gpb
+++ b/lib/gpb
@@ -1 +1 @@
-Subproject commit ed2c5452da8443bec0b5238e99346df5bfaa9b61
+Subproject commit 7b6fec17086cce8b1b32f174edb8aee60d9ba899
diff --git a/requirements.txt b/requirements.txt
index de81750..c769961 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,5 +2,5 @@ attrs==19.3.0
 mypy==0.780
 mypy-protobuf==1.20
 parsimonious==0.8.1
-protobuf==3.20.2
+protobuf==4.22.0
 typing==3.7.4.1