diff --git a/old_version/requirements.txt b/old_version/requirements.txt
index f443ea5..6cb22e2 100644
--- a/old_version/requirements.txt
+++ b/old_version/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.4
+nltk==3.4.5
 numpy==1.15.4
 tqdm==4.28.1
 tensorflow-gpu==1.12.0
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index fc5b856..5dde6df 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.4
+nltk==3.4.5
 numpy==1.15.4
 tqdm==4.28.1
 tensorflow-gpu==2.0.0-alpha0
diff --git a/tf1.12.0-eager/requirements.txt b/tf1.12.0-eager/requirements.txt
index 39ce504..025d9b1 100644
--- a/tf1.12.0-eager/requirements.txt
+++ b/tf1.12.0-eager/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.4
+nltk==3.4.5
 numpy==1.15.4
 tqdm==4.28.1
 tensorflow-gpu==1.12.0