diff --git a/files/create-sftp-user b/files/create-sftp-user
index 5df16b7..874264c 100755
--- a/files/create-sftp-user
+++ b/files/create-sftp-user
@@ -81,12 +81,20 @@ else
 fi
 
 # Add SSH keys to authorized_keys with valid permissions
-if [ -d "/home/$user/.ssh/keys" ]; then
-    for publickey in "/home/$user/.ssh/keys"/*; do
-        cat "$publickey" >> "/home/$user/.ssh/authorized_keys"
+userKeysQueuedDir="/home/$user/.ssh/keys"
+if [ -d "$userKeysQueuedDir" ]; then
+    userKeysAllowedFileTmp="$(mktemp)"
+    userKeysAllowedFile="/home/$user/.ssh/authorized_keys"
+
+    for publickey in "$userKeysQueuedDir"/*; do
+        cat "$publickey" >> "$userKeysAllowedFileTmp"
     done
-    chown "$uid" "/home/$user/.ssh/authorized_keys"
-    chmod 600 "/home/$user/.ssh/authorized_keys"
+
+    # Remove duplicate keys
+    sort < "$userKeysAllowedFileTmp" | uniq > "$userKeysAllowedFile"
+
+    chown "$uid" "$userKeysAllowedFile"
+    chmod 600 "$userKeysAllowedFile"
 fi
 
 # Make sure dirs exists
diff --git a/tests/run b/tests/run
index 6f92d84..dce27bd 100755
--- a/tests/run
+++ b/tests/run
@@ -13,6 +13,8 @@ testDir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 buildDir="$testDir/.."
 imageName="atmoz/sftp_test"
 buildOptions=(--tag "$imageName")
+sshKeyPri="/tmp/atmoz_sftp_test_rsa"
+sshKeyPub="/tmp/atmoz_sftp_test_rsa.pub"
 
 if [ "$argOutput" == "quiet" ]; then
     redirect="/dev/null"
@@ -45,12 +47,12 @@ function oneTimeSetUp() {
     fi
 
     # Generate temporary ssh keys for testing
-    if [ ! -f "/tmp/atmoz_sftp_test_rsa" ]; then
-        ssh-keygen -t rsa -f "/tmp/atmoz_sftp_test_rsa" -N '' > "$redirect" 2>&1
+    if [ ! -f "$sshKeyPri" ]; then
+        ssh-keygen -t rsa -f "$sshKeyPri" -N '' > "$redirect" 2>&1
     fi
 
     # Private key can not be read by others (sshd will complain)
-    chmod go-rw "/tmp/atmoz_sftp_test_rsa"
+    chmod go-rw "$sshKeyPri"
 }
 
 function oneTimeTearDown() {
@@ -104,7 +106,7 @@ function runSftpCommands() {
     done
 
     echo "$commands" | sftp \
-        -i "/tmp/atmoz_sftp_test_rsa" \
+        -i "$sshKeyPri" \
         -oStrictHostKeyChecking=no \
         -oUserKnownHostsFile=/dev/null \
         -b - "$user@$ip" \
@@ -252,7 +254,7 @@ function testCreateUsersUsingCombo() {
 
 function testWriteAccessToAutocreatedDirs() {
     docker run --name "$containerName" -d \
-        -v "/tmp/atmoz_sftp_test_rsa.pub":/home/test/.ssh/keys/id_rsa.pub:ro \
+        -v "$sshKeyPub":/home/test/.ssh/keys/id_rsa.pub:ro \
         "$imageName" "test::::testdir,dir with spaces" \
         > "$redirect" 2>&1
 
@@ -284,7 +286,7 @@ function testBindmountDirScript() {
 
     docker run --name "$containerName" -d \
         --privileged=true \
-        -v "/tmp/atmoz_sftp_test_rsa.pub":/home/custom/.ssh/keys/id_rsa.pub:ro \
+        -v "$sshKeyPub":/home/custom/.ssh/keys/id_rsa.pub:ro \
         -v "$containerTmpDir/custom/bindmount":/custom \
         -v "$containerTmpDir/mount.sh":/etc/sftp.d/mount.sh \
         "$imageName" custom:123 \
@@ -303,6 +305,21 @@ function testBindmountDirScript() {
     assertTrue "directory exist" $?
 }
 
+function testDuplicateSshKeys() {
+    docker run --name "$containerName" -d \
+        -v "$sshKeyPub":/home/user/.ssh/keys/key1.pub:ro \
+        -v "$sshKeyPub":/home/user/.ssh/keys/key2.pub:ro \
+        "$imageName" "user:" \
+        > "$redirect" 2>&1
+
+    waitForServer "$containerName"
+    assertTrue "waitForServer" $?
+
+    lines="$(docker exec "$containerName" sh -c \
+        "wc -l < /home/user/.ssh/authorized_keys")"
+    assertEquals "1" "$lines"
+}
+
 ##############################################################################
 ## Run
 ##############################################################################