diff --git a/build_helpers/bin/antlr-4.8-complete.jar b/build_helpers/bin/antlr-4.8-complete.jar
deleted file mode 100644
index 89a0640e2..000000000
Binary files a/build_helpers/bin/antlr-4.8-complete.jar and /dev/null differ
diff --git a/build_helpers/bin/antlr-4.9.3-complete.jar b/build_helpers/bin/antlr-4.9.3-complete.jar
new file mode 100644
index 000000000..749296fe7
Binary files /dev/null and b/build_helpers/bin/antlr-4.9.3-complete.jar differ
diff --git a/build_helpers/build_helpers.py b/build_helpers/build_helpers.py
index c1f6108f8..6419e2604 100644
--- a/build_helpers/build_helpers.py
+++ b/build_helpers/build_helpers.py
@@ -30,7 +30,7 @@ def run(self) -> None:
             command = [
                 "java",
                 "-jar",
-                str(build_dir / "bin" / "antlr-4.8-complete.jar"),
+                str(build_dir / "bin" / "antlr-4.9.3-complete.jar"),
                 "-Dlanguage=Python3",
                 "-o",
                 str(project_root / "omegaconf" / "grammar" / "gen"),
diff --git a/requirements/base.txt b/requirements/base.txt
index dab8a132e..5cad84a1f 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -1,4 +1,4 @@
-antlr4-python3-runtime==4.8
+antlr4-python3-runtime==4.9.*
 PyYAML>=5.1.0
 # Use dataclasses backport for Python 3.6.
 dataclasses;python_version=='3.6'