diff --git a/model-optimizer/install_prerequisites/install_prerequisites.sh b/model-optimizer/install_prerequisites/install_prerequisites.sh
index 6060158f96b..c7db058ddc4 100755
--- a/model-optimizer/install_prerequisites/install_prerequisites.sh
+++ b/model-optimizer/install_prerequisites/install_prerequisites.sh
@@ -72,7 +72,7 @@ if [[ $DISTRO == "centos" ]]; then
     fi
 elif [[ $DISTRO == "ubuntu" ]]; then
     sudo -E apt update
-    sudo -E apt -y install python3-pip python3-venv libgfortran3
+    sudo -E apt -y install python3-pip python3-venv libgfortran5
     python_binary=python3
 elif [[ "$OSTYPE" == "darwin"* ]]; then
     python_binary=python3
diff --git a/scripts/demo/demo_benchmark_app.sh b/scripts/demo/demo_benchmark_app.sh
index d04ca74aefa..c0fd828ee47 100755
--- a/scripts/demo/demo_benchmark_app.sh
+++ b/scripts/demo/demo_benchmark_app.sh
@@ -120,10 +120,10 @@ elif [[ $DISTRO == "ubuntu" ]]; then
     pip_binary=pip3
 
     system_ver=`cat /etc/lsb-release | grep -i "DISTRIB_RELEASE" | cut -d "=" -f2`
-    if [ $system_ver = "18.04" ]; then
-        sudo -E apt-get install -y libpng-dev
-    else
+    if [ $system_ver = "16.04" ]; then
         sudo -E apt-get install -y libpng12-dev
+    else
+        sudo -E apt-get install -y libpng-dev
     fi
 elif [[ "$OSTYPE" == "darwin"* ]]; then
     # check installed Python version
diff --git a/scripts/demo/demo_security_barrier_camera.sh b/scripts/demo/demo_security_barrier_camera.sh
index 6f3f60eeb1e..ca71a7e4ecd 100755
--- a/scripts/demo/demo_security_barrier_camera.sh
+++ b/scripts/demo/demo_security_barrier_camera.sh
@@ -89,10 +89,10 @@ elif [[ $DISTRO == "ubuntu" ]]; then
     pip_binary=pip3
 
     system_ver=`cat /etc/lsb-release | grep -i "DISTRIB_RELEASE" | cut -d "=" -f2`
-    if [ $system_ver = "18.04" ]; then
-        sudo -E apt-get install -y libpng-dev
-    else
+    if [ $system_ver = "16.04" ]; then
         sudo -E apt-get install -y libpng12-dev
+    else
+        sudo -E apt-get install -y libpng-dev
     fi
 elif [[ "$OSTYPE" == "darwin"* ]]; then
     # check installed Python version
diff --git a/scripts/demo/demo_squeezenet_download_convert_run.sh b/scripts/demo/demo_squeezenet_download_convert_run.sh
index bd36524e665..86e1e3286da 100755
--- a/scripts/demo/demo_squeezenet_download_convert_run.sh
+++ b/scripts/demo/demo_squeezenet_download_convert_run.sh
@@ -116,10 +116,10 @@ elif [[ $DISTRO == "ubuntu" ]]; then
     pip_binary=pip3
 
     system_ver=`cat /etc/lsb-release | grep -i "DISTRIB_RELEASE" | cut -d "=" -f2`
-    if [ $system_ver = "18.04" ]; then
-        sudo -E apt-get install -y libpng-dev
-    else
+    if [ $system_ver = "16.04" ]; then
         sudo -E apt-get install -y libpng12-dev
+    else
+        sudo -E apt-get install -y libpng-dev
     fi
 elif [[ "$OSTYPE" == "darwin"* ]]; then
     # check installed Python version