diff --git a/docker_test.sh b/docker_test.sh
index 36a4e2f..77e6bb6 100755
--- a/docker_test.sh
+++ b/docker_test.sh
@@ -71,20 +71,32 @@ function create_docker_image {
 
     # Aside from checking the GPG signatures, we also compare against this known-good
     # SHA-256 hash just in case.
+    get_openssh '4.0p1' '5adb9b2c2002650e15216bf94ed9db9541d9a17c96fcd876784861a8890bc92b'
     get_openssh '5.6p1' '538af53b2b8162c21a293bb004ae2bdb141abd250f61b4cea55244749f3c6c2b'
     get_openssh '8.0p1' 'bd943879e69498e8031eb6b7f44d08cdc37d59a7ab689aa0b437320c3481fd68'
 
     # Compile the versions of OpenSSH.
+    compile_openssh '4.0p1'
     compile_openssh '5.6p1'
     compile_openssh '8.0p1'
 
     # Rename the default config files so we know they are our originals.
+    mv openssh-4.0p1/sshd_config sshd_config-4.0p1_orig
     mv openssh-5.6p1/sshd_config sshd_config-5.6p1_orig
     mv openssh-8.0p1/sshd_config sshd_config-8.0p1_orig
 
 
     # Create the configurations for each test.
 
+
+    #
+    # OpenSSH v4.0p1
+    #
+
+    # Test 1: Basic test.
+    create_openssh_config '4.0p1' 'test1' "HostKey /etc/ssh/ssh1_host_key\nHostKey /etc/ssh/ssh_host_rsa_key_1024\nHostKey /etc/ssh/ssh_host_dsa_key"
+
+
     #
     # OpenSSH v5.6p1
     #
@@ -164,8 +176,15 @@ function get_openssh {
 
     echo -e "\nGetting OpenSSH $1 signature...\n"
     wget https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-$1.tar.gz.asc
+    openssh_sig=openssh-$1.tar.gz.asc
 
-    local gpg_verify=`gpg --verify openssh-$1.tar.gz.asc openssh-$1.tar.gz 2>&1`
+    # Older releases were .sigs.
+    if [[ ! -f $openssh_sig ]]; then
+	wget https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-$1.tar.gz.sig
+	openssh_sig=openssh-$1.tar.gz.sig
+    fi
+
+    local gpg_verify=`gpg --verify $openssh_sig openssh-$1.tar.gz 2>&1`
     if [[ $gpg_verify != *"Good signature from \"Damien Miller "* ]]; then
         echo -e "\n\n${REDB}Error: OpenSSH signature invalid!\n$gpg_verify\n\nTerminating.${CLR}"
         exit -1
@@ -246,12 +265,14 @@ TEST_RESULT_DIR=`mktemp -d /tmp/ssh-audit_test-results_XXXXXXXXXX`
 
 # Now run all the tests.
 echo -e "\nRunning tests..."
+run_openssh_test '4.0p1' 'test1'
+echo
 run_openssh_test '5.6p1' 'test1'
 run_openssh_test '5.6p1' 'test2'
 run_openssh_test '5.6p1' 'test3'
 run_openssh_test '5.6p1' 'test4'
 run_openssh_test '5.6p1' 'test5'
-echo ""
+echo
 run_openssh_test '8.0p1' 'test1'
 run_openssh_test '8.0p1' 'test2'
 run_openssh_test '8.0p1' 'test3'
diff --git a/test/docker/Dockerfile b/test/docker/Dockerfile
index 739be49..41a62c2 100644
--- a/test/docker/Dockerfile
+++ b/test/docker/Dockerfile
@@ -1,10 +1,12 @@
 FROM ubuntu:16.04
 
+COPY openssh-4.0p1/sshd /openssh/sshd-4.0p1
 COPY openssh-5.6p1/sshd /openssh/sshd-5.6p1
 COPY openssh-8.0p1/sshd /openssh/sshd-8.0p1
 
 COPY sshd_config* /etc/ssh/
 COPY ssh_host_* /etc/ssh/
+COPY ssh1_host_* /etc/ssh/
 COPY moduli_1024 /usr/local/etc/moduli
 
 COPY debug.sh /debug.sh
diff --git a/test/docker/expected_results/openssh_4.0p1_test1.txt b/test/docker/expected_results/openssh_4.0p1_test1.txt
new file mode 100644
index 0000000..33e1967
--- /dev/null
+++ b/test/docker/expected_results/openssh_4.0p1_test1.txt
@@ -0,0 +1,136 @@
+# general
+(gen) banner: SSH-1.99-OpenSSH_4.0
+(gen) protocol SSH1 enabled
+(gen) software: OpenSSH 4.0
+(gen) compatibility: OpenSSH 3.9-6.6, Dropbear SSH 0.53+ (some functionality from 0.52)
+(gen) compression: enabled (zlib)
+
+# security
+(cve) CVE-2016-3115                       -- (CVSSv2: 5.5) bypass command restrictions via crafted X11 forwarding data
+(cve) CVE-2014-1692                       -- (CVSSv2: 7.5) cause DoS via triggering error condition (memory corruption)
+(cve) CVE-2012-0814                       -- (CVSSv2: 3.5) leak data via debug messages
+(cve) CVE-2011-5000                       -- (CVSSv2: 3.5) cause DoS via large value in certain length field (memory consumption)
+(cve) CVE-2010-5107                       -- (CVSSv2: 5.0) cause DoS via large number of connections (slot exhaustion)
+(cve) CVE-2010-4755                       -- (CVSSv2: 4.0) cause DoS via crafted glob expression (CPU and memory consumption)
+(cve) CVE-2010-4478                       -- (CVSSv2: 7.5) bypass authentication check via crafted values
+(cve) CVE-2008-5161                       -- (CVSSv2: 2.6) recover plaintext data from ciphertext
+(cve) CVE-2008-4109                       -- (CVSSv2: 5.0) cause DoS via multiple login attempts (slot exhaustion)
+(cve) CVE-2008-1657                       -- (CVSSv2: 6.5) bypass command restrictions via modifying session file
+(cve) CVE-2008-1483                       -- (CVSSv2: 6.9) hijack forwarded X11 connections
+(cve) CVE-2007-4752                       -- (CVSSv2: 7.5) privilege escalation via causing an X client to be trusted
+(cve) CVE-2007-2243                       -- (CVSSv2: 5.0) discover valid usernames through different responses
+(cve) CVE-2006-5052                       -- (CVSSv2: 5.0) discover valid usernames through different responses
+(cve) CVE-2006-5051                       -- (CVSSv2: 9.3) cause DoS or execute arbitrary code (double free)
+(cve) CVE-2006-4924                       -- (CVSSv2: 7.8) cause DoS via crafted packet (CPU consumption)
+(cve) CVE-2006-0225                       -- (CVSSv2: 4.6) execute arbitrary code
+(cve) CVE-2005-2798                       -- (CVSSv2: 5.0) leak data about authentication credentials
+
+# key exchange algorithms
+(kex) diffie-hellman-group-exchange-sha1 (1024-bit) -- [fail] using small 1024-bit modulus
+                                                    `- [warn] using weak hashing algorithm
+                                                    `- [info] available since OpenSSH 2.3.0
+(kex) diffie-hellman-group14-sha1         -- [warn] using weak hashing algorithm
+                                          `- [info] available since OpenSSH 3.9, Dropbear SSH 0.53
+(kex) diffie-hellman-group1-sha1          -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [fail] disabled (in client) since OpenSSH 7.0, logjam attack
+                                          `- [warn] using small 1024-bit modulus
+                                          `- [warn] using weak hashing algorithm
+                                          `- [info] available since OpenSSH 2.3.0, Dropbear SSH 0.28
+
+# host-key algorithms
+(key) ssh-rsa (1024-bit)                  -- [fail] using small 1024-bit modulus
+                                          `- [info] available since OpenSSH 2.5.0, Dropbear SSH 0.28
+(key) ssh-dss                             -- [fail] removed (in server) and disabled (in client) since OpenSSH 7.0, weak algorithm
+                                          `- [warn] using small 1024-bit modulus
+                                          `- [warn] using weak random number generator could reveal the key
+                                          `- [info] available since OpenSSH 2.1.0, Dropbear SSH 0.28
+
+# encryption algorithms (ciphers)
+(enc) aes128-cbc                          -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] using weak cipher mode
+                                          `- [info] available since OpenSSH 2.3.0, Dropbear SSH 0.28
+(enc) 3des-cbc                            -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.4, unsafe algorithm
+                                          `- [warn] using weak cipher
+                                          `- [warn] using weak cipher mode
+                                          `- [warn] using small 64-bit block size
+                                          `- [info] available since OpenSSH 1.2.2, Dropbear SSH 0.28
+(enc) blowfish-cbc                        -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [fail] disabled since Dropbear SSH 0.53
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using weak cipher mode
+                                          `- [warn] using small 64-bit block size
+                                          `- [info] available since OpenSSH 1.2.2, Dropbear SSH 0.28
+(enc) cast128-cbc                         -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using weak cipher mode
+                                          `- [warn] using small 64-bit block size
+                                          `- [info] available since OpenSSH 2.1.0
+(enc) arcfour                             -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using weak cipher
+                                          `- [info] available since OpenSSH 2.1.0
+(enc) aes192-cbc                          -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] using weak cipher mode
+                                          `- [info] available since OpenSSH 2.3.0
+(enc) aes256-cbc                          -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] using weak cipher mode
+                                          `- [info] available since OpenSSH 2.3.0, Dropbear SSH 0.47
+(enc) rijndael-cbc@lysator.liu.se         -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using weak cipher mode
+                                          `- [info] available since OpenSSH 2.3.0
+(enc) aes128-ctr                          -- [info] available since OpenSSH 3.7, Dropbear SSH 0.52
+(enc) aes192-ctr                          -- [info] available since OpenSSH 3.7
+(enc) aes256-ctr                          -- [info] available since OpenSSH 3.7, Dropbear SSH 0.52
+
+# message authentication code algorithms
+(mac) hmac-md5                            -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using encrypt-and-MAC mode
+                                          `- [warn] using weak hashing algorithm
+                                          `- [info] available since OpenSSH 2.1.0, Dropbear SSH 0.28
+(mac) hmac-sha1                           -- [warn] using encrypt-and-MAC mode
+                                          `- [warn] using weak hashing algorithm
+                                          `- [info] available since OpenSSH 2.1.0, Dropbear SSH 0.28
+(mac) hmac-ripemd160                      -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using encrypt-and-MAC mode
+                                          `- [info] available since OpenSSH 2.5.0
+(mac) hmac-ripemd160@openssh.com          -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using encrypt-and-MAC mode
+                                          `- [info] available since OpenSSH 2.1.0
+(mac) hmac-sha1-96                        -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using encrypt-and-MAC mode
+                                          `- [warn] using weak hashing algorithm
+                                          `- [info] available since OpenSSH 2.5.0, Dropbear SSH 0.47
+(mac) hmac-md5-96                         -- [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
+                                          `- [warn] disabled (in client) since OpenSSH 7.2, legacy algorithm
+                                          `- [warn] using encrypt-and-MAC mode
+                                          `- [warn] using weak hashing algorithm
+                                          `- [info] available since OpenSSH 2.5.0
+
+# fingerprints
+(fin) ssh-rsa: SHA256:YZ457EBcJTSxRKI3yXRgtAj3PBf5B9/F36b1SVooml4
+
+# algorithm recommendations (for OpenSSH 4.0)
+(rec) !ssh-rsa                            -- key algorithm to change (increase modulus size to 2048 bits or larger) 
+(rec) -3des-cbc                           -- enc algorithm to remove 
+(rec) -aes128-cbc                         -- enc algorithm to remove 
+(rec) -aes192-cbc                         -- enc algorithm to remove 
+(rec) -aes256-cbc                         -- enc algorithm to remove 
+(rec) -arcfour                            -- enc algorithm to remove 
+(rec) -blowfish-cbc                       -- enc algorithm to remove 
+(rec) -cast128-cbc                        -- enc algorithm to remove 
+(rec) -diffie-hellman-group-exchange-sha1 -- kex algorithm to remove 
+(rec) -diffie-hellman-group1-sha1         -- kex algorithm to remove 
+(rec) -hmac-md5                           -- mac algorithm to remove 
+(rec) -hmac-md5-96                        -- mac algorithm to remove 
+(rec) -hmac-ripemd160                     -- mac algorithm to remove 
+(rec) -hmac-ripemd160@openssh.com         -- mac algorithm to remove 
+(rec) -hmac-sha1-96                       -- mac algorithm to remove 
+(rec) -rijndael-cbc@lysator.liu.se        -- enc algorithm to remove 
+(rec) -ssh-dss                            -- key algorithm to remove 
+
diff --git a/test/docker/ssh1_host_key b/test/docker/ssh1_host_key
new file mode 100644
index 0000000..c98971c
Binary files /dev/null and b/test/docker/ssh1_host_key differ
diff --git a/test/docker/ssh1_host_key.pub b/test/docker/ssh1_host_key.pub
new file mode 100644
index 0000000..b66c66f
--- /dev/null
+++ b/test/docker/ssh1_host_key.pub
@@ -0,0 +1 @@
+1024 35 150823875409720459951648542224727752099073441604930026287525797402159071426070997897033651155038337251362080634963146983947007228274330777134724953282680928153520263171933106732090266742784258910450489054624715996015082463159338507115031336180486071622718809324273851629938883104520608180885444242395900180011 root@ubuntu1604server