diff --git a/.github/workflows/integration_tests.yml b/.github/workflows/integration_tests.yml
index a286cfa..95747ab 100644
--- a/.github/workflows/integration_tests.yml
+++ b/.github/workflows/integration_tests.yml
@@ -11,10 +11,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        psql_version: ['14.4', '15.1']
+        psql_version: ['12.13', '13.9', '14.4', '15.1']
         python_version: ['3.8', '3.9', '3.10']
 
-    name: Integration test for PostgreSQL ${{ matrix.psql_version }} and Python ${{ matrix.python_version }}
+    name: PostgreSQL ${{ matrix.psql_version }} and Python ${{ matrix.python_version }} integration test
     runs-on: ubuntu-latest
 
     steps:
@@ -83,4 +83,4 @@ jobs:
         run: sudo pg_lock_tracer -x ~/postgresql/bin/${{ matrix.psql_version }}/bin/postgres -v -p $(pidof postgres) --statistics --dry-run
 
       - name: Check that pg_lw_lock_tracer can be executed
-        run: sudo pg_lw_lock_tracer -p $(pidof postgres) --dry-run
\ No newline at end of file
+        run: sudo pg_lw_lock_tracer -p $(pidof postgres) --dry-run
diff --git a/README.md b/README.md
index d89074c..36bd24c 100644
--- a/README.md
+++ b/README.md
@@ -767,7 +767,7 @@ pip install git+https://github.com/jnidzwetzki/pg-lock-tracer
 ```
 
 ## PostgreSQL Build
-The software is tested with PostgreSQL 14 and PostgreSQL 15. In order to be able to attach the _uprobes_ to the functions, they should not to be optimized away (e.g., inlined) during the compilation of PostgreSQL. Otherwise errors like `Unable to locate function XXX` will occur when `pg_lock_tracer` is started.
+The software is tested with PostgreSQL versions 12, 13, 14 and 15. In order to be able to attach the _uprobes_ to the functions, they should not to be optimized away (e.g., inlined) during the compilation of PostgreSQL. Otherwise errors like `Unable to locate function XXX` will occur when `pg_lock_tracer` is started.
 
 It is recommended to compile PostgreSQL with following CFLAGS: `CFLAGS="-ggdb -Og -g3 -fno-omit-frame-pointer"`.