diff --git a/.travis.yml b/.travis.yml
index e6a5ba7..93ef5eb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,7 +20,7 @@ install:
     - pip install -U nose pip setuptools
     - pip install coveralls codecov requests-mock
     - pip install git+https://github.com/kbandla/pydeep.git
-    - pip install .[fileobjects,neo,openioc]
+    - pip install .[fileobjects,neo,openioc,virustotal]
     - pushd tests
     - git clone https://github.com/viper-framework/viper-test-files.git
     - popd
diff --git a/pymisp/tools/vtreportobject.py b/pymisp/tools/vtreportobject.py
index 5a4858b..927ca26 100644
--- a/pymisp/tools/vtreportobject.py
+++ b/pymisp/tools/vtreportobject.py
@@ -4,7 +4,12 @@
 import re
 
 import requests
-import validators
+try:
+    import validators
+    has_validators = True
+except ImportError:
+    has_validators = False
+
 
 from .abstractgenerator import AbstractMISPObjectGenerator
 from .. import InvalidMISPObject
@@ -48,6 +53,8 @@ class VTReportObject(AbstractMISPObjectGenerator):
 
         :ioc: Indicator to search VirusTotal for
         '''
+        if not has_validators:
+            raise Exception('You need to install validators: pip install validators')
         if validators.url(ioc):
             return "url"
         elif re.match(r"\b([a-fA-F0-9]{32}|[a-fA-F0-9]{40}|[a-fA-F0-9]{64})\b", ioc):
diff --git a/setup.py b/setup.py
index 528b2d6..5d7391d 100644
--- a/setup.py
+++ b/setup.py
@@ -30,7 +30,8 @@ setup(
     install_requires=['six', 'requests', 'python-dateutil', 'jsonschema', 'setuptools>=36.4'],
     extras_require={'fileobjects': ['lief>=0.8', 'python-magic'],
                     'neo': ['py2neo'],
-                    'openioc': ['beautifulsoup4']},
+                    'openioc': ['beautifulsoup4'],
+                    'virustotal': ['validators']},
     tests_require=[
         'jsonschema',
         'python-dateutil',