diff --git a/lib/constants.py b/lib/constants.py
index de40522b261d1cfcaf3948615bf54d065c018f1e..5ddf13c8ec66ff3e26f2f8965b6c8af18abecaad 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -146,6 +146,8 @@ SSH_HOST_DSA_PRIV = SSH_CONFIG_DIR + "ssh_host_dsa_key"
 SSH_HOST_DSA_PUB = SSH_HOST_DSA_PRIV + ".pub"
 SSH_HOST_RSA_PRIV = SSH_CONFIG_DIR + "ssh_host_rsa_key"
 SSH_HOST_RSA_PUB = SSH_HOST_RSA_PRIV + ".pub"
+SSH = "ssh"
+SCP = "scp"
 
 # reboot types
 INSTANCE_REBOOT_SOFT = "soft"
diff --git a/lib/ssh.py b/lib/ssh.py
index 6481d70fab24baddd325815d7989a507733df2d1..2b06a585f46b992bdcd6ce9ae09bcc314741b786 100644
--- a/lib/ssh.py
+++ b/lib/ssh.py
@@ -116,7 +116,7 @@ class SshRunner:
       The ssh call to run 'command' on the remote host.
 
     """
-    argv = ["ssh", "-q"]
+    argv = [constants.SSH, "-q"]
     argv.extend(KNOWN_HOSTS_OPTS)
     argv.append(self._GetHostKeyAliasOption())
     if batch:
@@ -171,7 +171,7 @@ class SshRunner:
       logger.Error("file %s must be an absolute path" % (filename))
       return False
 
-    command = ["scp", "-q", "-p"]
+    command = [constants.SCP, "-q", "-p"]
     command.extend(KNOWN_HOSTS_OPTS)
     command.extend(BATCH_MODE_OPTS)
     command.append(self._GetHostKeyAliasOption())