diff --git a/rake_nltk/rake.py b/rake_nltk/rake.py
index 53f5b9d..8a36c8b 100644
--- a/rake_nltk/rake.py
+++ b/rake_nltk/rake.py
@@ -53,7 +53,11 @@ def __init__(
         # If stopwords not provided we use language stopwords by default.
         self.stopwords = stopwords
         if self.stopwords is None:
-            self.stopwords = nltk.corpus.stopwords.words(language)
+            try:
+                self.stopwords = nltk.corpus.stopwords.words(language)
+            except LookupError:
+                nltk.download('stopwords')
+                self.stopwords = nltk.corpus.stopwords.words(language)
 
         # If punctuations are not provided we ignore all punctuation symbols.
         self.punctuations = punctuations
@@ -78,7 +82,11 @@ def extract_keywords_from_text(self, text):
 
         :param text: Text to extract keywords from, provided as a string.
         """
-        sentences = nltk.tokenize.sent_tokenize(text)
+        try:
+            sentences = nltk.tokenize.sent_tokenize(text)
+        except LookupError:
+            nltk.download('punkt')
+            sentences = nltk.tokenize.sent_tokenize(text)
         self.extract_keywords_from_sentences(sentences)
 
     def extract_keywords_from_sentences(self, sentences):
diff --git a/setup.py b/setup.py
index 8d24245..e3b4a30 100644
--- a/setup.py
+++ b/setup.py
@@ -12,30 +12,6 @@
     long_description = f.read()
 
 
-def _post_install():
-    """Post installation nltk corpus downloads."""
-    import nltk
-
-    nltk.download("punkt")
-    nltk.download("stopwords")
-
-
-class PostDevelop(develop):
-    """Post-installation for development mode."""
-
-    def run(self):
-        develop.run(self)
-        self.execute(_post_install, [], msg="Running post installation tasks")
-
-
-class PostInstall(install):
-    """Post-installation for production mode."""
-
-    def run(self):
-        install.run(self)
-        self.execute(_post_install, [], msg="Running post installation tasks")
-
-
 # Get package and author details.
 about = {}
 with open(path.join(here, "rake_nltk", "__version__.py")) as f:
@@ -77,6 +53,5 @@ def run(self):
         "Topic :: Software Development :: Build Tools",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],
-    install_requires=["nltk"],
-    cmdclass={"develop": PostDevelop, "install": PostInstall},
+    install_requires=["nltk"]
 )