diff --git a/nselib/smbauth.lua b/nselib/smbauth.lua
index 38c12adc3..bee8d99c4 100644
--- a/nselib/smbauth.lua
+++ b/nselib/smbauth.lua
@@ -921,6 +921,7 @@ if not unittest.testing() then
 end
 
 test_suite = unittest.TestSuite:new()
+if have_ssl then
 test_suite:add_test(unittest.equal(
     stdnse.tohex(select(-1, lm_create_hash("passphrase"))),
     "855c3697d9979e78ac404c4ba2c66533"
@@ -945,5 +946,9 @@ test_suite:add_test(unittest.equal(
     ),
   "ntlm_create_hash"
   )
+else
+  test_suite:add_test(unittest.is_false(lm_create_hash("a"), "lm_create_hash"))
+  test_suite:add_test(unittest.is_false(ntlm_create_hash("a"), "ntlm_create_hash"))
+end
 
 return _ENV;
diff --git a/nselib/unittest.lua b/nselib/unittest.lua
index b7e799708..22807c83a 100644
--- a/nselib/unittest.lua
+++ b/nselib/unittest.lua
@@ -159,13 +159,17 @@ run_tests = function(to_test)
   local fails = stdnse.output_table()
   for _,lib in ipairs(to_test) do
     stdnse.debug1("Testing %s", lib)
-    local thelib = require(lib)
-    local failed = 0
-    if rawget(thelib,"test_suite") ~= nil then
-      failed = thelib.test_suite()
-    end
-    if failed ~= 0 then
-      fails[lib] = failed
+    local status, thelib = pcall(require, lib)
+    if not status then
+      stdnse.debug1("Failed to load %s", lib)
+    else
+      local failed = 0
+      if rawget(thelib,"test_suite") ~= nil then
+        failed = thelib.test_suite()
+      end
+      if failed ~= 0 then
+        fails[lib] = failed
+      end
     end
   end
   return fails