diff --git a/README.md b/README.md
index 15421579..0bc7c725 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ sudo apt-get install curl
 curl -fsSL https://raw.githubusercontent.com/dreal/dreal4/master/setup/ubuntu/18.04/install.sh | sudo bash
 
 # Test the installation.
-DREAL_VERSION=4.20.12.1
+DREAL_VERSION=4.21.06.1
 /opt/dreal/${DREAL_VERSION}/bin/dreal
 ```
 
@@ -196,7 +196,7 @@ export PKG_CONFIG_PATH=/usr/local/opt/ibex@2.7.4/share/pkgconfig:${PKG_CONFIG_PA
 Ubuntu 20.04 / 18.04:
 
 ```bash
-export PKG_CONFIG_PATH=/opt/dreal/4.20.12.1/lib/pkgconfig:/opt/libibex/2.7.4/share/pkgconfig:${PKG_CONFIG_PATH}
+export PKG_CONFIG_PATH=/opt/dreal/4.21.06.1/lib/pkgconfig:/opt/libibex/2.7.4/share/pkgconfig:${PKG_CONFIG_PATH}
 ```
 
 Then, `pkg-config dreal --cflags` and `pkg-config dreal --libs` should
diff --git a/dreal/__init__.py b/dreal/__init__.py
index c6283962..1725505d 100644
--- a/dreal/__init__.py
+++ b/dreal/__init__.py
@@ -20,7 +20,7 @@ def logical_or(*formulas):
     return reduce(__logical_or, formulas)
 
 
-__version__ = "4.20.12.1".replace(".0", ".")
+__version__ = "4.21.06.1".replace(".0", ".")
 
 # Add aliases
 And = logical_and
diff --git a/setup.py b/setup.py
index 45991af1..30302a23 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@
 from setuptools.command.bdist_egg import bdist_egg as _bdist_egg
 from setuptools.command.develop import develop as _develop
 
-VERSION = '4.20.12.1'.replace(".0", ".")
+VERSION = '4.21.06.1'.replace(".0", ".")
 ROOT_DIR = os.path.abspath(os.path.dirname(__file__))
 SRC_DIR = os.path.join(ROOT_DIR)
 
diff --git a/setup/ubuntu/18.04/install.sh b/setup/ubuntu/18.04/install.sh
index 1f13ce07..72a2edeb 100755
--- a/setup/ubuntu/18.04/install.sh
+++ b/setup/ubuntu/18.04/install.sh
@@ -13,10 +13,10 @@ add-apt-repository ppa:dreal/dreal --no-update -y  # For libibex-dev
 apt-get update || (sleep 30; apt-get update)
 
 # Install dReal
-DREAL_VERSION=4.20.12.1
+DREAL_VERSION=4.21.06.1
 DREAL_DEBNAME=dreal_${DREAL_VERSION}_amd64.deb
 DREAL_URL=https://github.com/dreal/dreal4/releases/download/${DREAL_VERSION}/${DREAL_DEBNAME}
-DREAL_SHA256=8e1cc5b1d4be3fea534f1db27cfaddd5e0606e57d60bc95ce1a3d19597812938
+DREAL_SHA256=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
 apt-get install --no-install-recommends wget -y
 wget "${DREAL_URL}"
 if echo "${DREAL_SHA256}  ${DREAL_DEBNAME}" | sha256sum -c; then
diff --git a/setup/ubuntu/20.04/install.sh b/setup/ubuntu/20.04/install.sh
index 1f13ce07..72a2edeb 100755
--- a/setup/ubuntu/20.04/install.sh
+++ b/setup/ubuntu/20.04/install.sh
@@ -13,10 +13,10 @@ add-apt-repository ppa:dreal/dreal --no-update -y  # For libibex-dev
 apt-get update || (sleep 30; apt-get update)
 
 # Install dReal
-DREAL_VERSION=4.20.12.1
+DREAL_VERSION=4.21.06.1
 DREAL_DEBNAME=dreal_${DREAL_VERSION}_amd64.deb
 DREAL_URL=https://github.com/dreal/dreal4/releases/download/${DREAL_VERSION}/${DREAL_DEBNAME}
-DREAL_SHA256=8e1cc5b1d4be3fea534f1db27cfaddd5e0606e57d60bc95ce1a3d19597812938
+DREAL_SHA256=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
 apt-get install --no-install-recommends wget -y
 wget "${DREAL_URL}"
 if echo "${DREAL_SHA256}  ${DREAL_DEBNAME}" | sha256sum -c; then
diff --git a/tools/dreal.bzl b/tools/dreal.bzl
index 215d4358..7ff87df9 100644
--- a/tools/dreal.bzl
+++ b/tools/dreal.bzl
@@ -1,7 +1,7 @@
 # Based on Drake's drake.bzl file,
 # https://github.com/RobotLocomotion/drake/blob/master/tools/drake.bzl.
 
-DREAL_VERSION = "4.20.12.1"
+DREAL_VERSION = "4.21.06.1"
 
 DREAL_PREFIX = "opt/dreal/%s" % DREAL_VERSION