diff --git a/vpnsetup.sh b/vpnsetup.sh
index 3a6ad7f..f87bc0e 100644
--- a/vpnsetup.sh
+++ b/vpnsetup.sh
@@ -119,7 +119,7 @@ SWAN_VER=3.17
 SWAN_FILE="libreswan-${SWAN_VER}.tar.gz"
 SWAN_URL="https://download.libreswan.org/$SWAN_FILE"
 wget -t 3 -T 30 -nv -O "$SWAN_FILE" "$SWAN_URL"
-[ ! -f "$SWAN_FILE" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
+[ "$?" != "0" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
 /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
 tar xvzf "$SWAN_FILE" && /bin/rm -f "$SWAN_FILE"
 cd "libreswan-$SWAN_VER" || { echo "Failed to enter Libreswan source dir. Aborting."; exit 1; }
diff --git a/vpnsetup_centos.sh b/vpnsetup_centos.sh
index a1eb24f..4dddee0 100644
--- a/vpnsetup_centos.sh
+++ b/vpnsetup_centos.sh
@@ -150,8 +150,9 @@ if grep -qs "release 6" /etc/redhat-release; then
   RPM1=libevent2-2.0.22-1.el6.x86_64.rpm
   RPM2=libevent2-devel-2.0.22-1.el6.x86_64.rpm
   wget -t 3 -T 30 -nv -O "$RPM1" "$LE2_URL/$RPM1"
+  [ "$?" != "0" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
   wget -t 3 -T 30 -nv -O "$RPM2" "$LE2_URL/$RPM2"
-  [ ! -f "$RPM1" ] || [ ! -f "$RPM2" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
+  [ "$?" != "0" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
   rpm -ivh --force "$RPM1" "$RPM2" && /bin/rm -f "$RPM1" "$RPM2"
 elif grep -qs "release 7" /etc/redhat-release; then
   yum -y install libevent-devel
@@ -162,7 +163,7 @@ SWAN_VER=3.17
 SWAN_FILE="libreswan-${SWAN_VER}.tar.gz"
 SWAN_URL="https://download.libreswan.org/$SWAN_FILE"
 wget -t 3 -T 30 -nv -O "$SWAN_FILE" "$SWAN_URL"
-[ ! -f "$SWAN_FILE" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
+[ "$?" != "0" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
 /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
 tar xvzf "$SWAN_FILE" && /bin/rm -f "$SWAN_FILE"
 cd "libreswan-$SWAN_VER" || { echo "Failed to enter Libreswan source dir. Aborting."; exit 1; }
diff --git a/vpnupgrade_Libreswan.sh b/vpnupgrade_Libreswan.sh
index 80ff982..d434a1c 100644
--- a/vpnupgrade_Libreswan.sh
+++ b/vpnupgrade_Libreswan.sh
@@ -103,7 +103,7 @@ apt-get -y --no-install-recommends install xmlto
 SWAN_FILE="libreswan-${SWAN_VER}.tar.gz"
 SWAN_URL="https://download.libreswan.org/$SWAN_FILE"
 wget -t 3 -T 30 -nv -O "$SWAN_FILE" "$SWAN_URL"
-[ ! -f "$SWAN_FILE" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
+[ "$?" != "0" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
 /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
 tar xvzf "$SWAN_FILE" && /bin/rm -f "$SWAN_FILE"
 cd "libreswan-$SWAN_VER" || { echo "Failed to enter Libreswan source dir. Aborting."; exit 1; }
diff --git a/vpnupgrade_Libreswan_centos.sh b/vpnupgrade_Libreswan_centos.sh
index 3e17eee..6244f6a 100644
--- a/vpnupgrade_Libreswan_centos.sh
+++ b/vpnupgrade_Libreswan_centos.sh
@@ -120,8 +120,9 @@ if grep -qs "release 6" /etc/redhat-release; then
   RPM1=libevent2-2.0.22-1.el6.x86_64.rpm
   RPM2=libevent2-devel-2.0.22-1.el6.x86_64.rpm
   wget -t 3 -T 30 -nv -O "$RPM1" "$LE2_URL/$RPM1"
+  [ "$?" != "0" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
   wget -t 3 -T 30 -nv -O "$RPM2" "$LE2_URL/$RPM2"
-  [ ! -f "$RPM1" ] || [ ! -f "$RPM2" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
+  [ "$?" != "0" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
   rpm -ivh --force "$RPM1" "$RPM2" && /bin/rm -f "$RPM1" "$RPM2"
 elif grep -qs "release 7" /etc/redhat-release; then
   yum -y install libevent-devel
@@ -131,7 +132,7 @@ fi
 SWAN_FILE="libreswan-${SWAN_VER}.tar.gz"
 SWAN_URL="https://download.libreswan.org/$SWAN_FILE"
 wget -t 3 -T 30 -nv -O "$SWAN_FILE" "$SWAN_URL"
-[ ! -f "$SWAN_FILE" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
+[ "$?" != "0" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
 /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
 tar xvzf "$SWAN_FILE" && /bin/rm -f "$SWAN_FILE"
 cd "libreswan-$SWAN_VER" || { echo "Failed to enter Libreswan source dir. Aborting."; exit 1; }