diff --git a/README.md b/README.md
index 4b30a8d..c050ddc 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ It exists solely for educational reasons.
 ## How to Use it
 
 ```
-python3 compute.py '2*(3+4)'
+python3 arithmetic_expressions/compute.py '2*(3+4)'
 ```
 and you should receive `14` as the result.
 This is perhaps not so surprising, but you can also run
diff --git a/__init__.py b/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/arithmetic_expressions/__init__.py b/arithmetic_expressions/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/compute.py b/arithmetic_expressions/compute.py
similarity index 80%
rename from compute.py
rename to arithmetic_expressions/compute.py
index 57e95b5..fb16717 100644
--- a/compute.py
+++ b/arithmetic_expressions/compute.py
@@ -1,13 +1,13 @@
 import sys
 import operator
-import parser
-
+from arithmetic_expressions import parser
 
 operations = {
     parser.TokenType.T_PLUS: operator.add,
     parser.TokenType.T_MINUS: operator.sub,
     parser.TokenType.T_MULT: operator.mul,
-    parser.TokenType.T_DIV: operator.truediv
+    parser.TokenType.T_DIV: operator.truediv,
+    parser.TokenType.T_MODULO: operator.mod
 }
 
 
diff --git a/parser.py b/arithmetic_expressions/parser.py
similarity index 94%
rename from parser.py
rename to arithmetic_expressions/parser.py
index c1d3cc4..4c40509 100644
--- a/parser.py
+++ b/arithmetic_expressions/parser.py
@@ -11,6 +11,7 @@ class TokenType(enum.Enum):
     T_LPAR = 5
     T_RPAR = 6
     T_END = 7
+    T_MODULO = 8
 
 
 class Node:
@@ -27,7 +28,9 @@ def lexical_analysis(s):
         '*': TokenType.T_MULT,
         '/': TokenType.T_DIV,
         '(': TokenType.T_LPAR,
-        ')': TokenType.T_RPAR}
+        ')': TokenType.T_RPAR,
+        '%': TokenType.T_MODULO
+    }
 
     tokens = []
     for c in s:
@@ -65,7 +68,7 @@ def parse_e(tokens):
 def parse_e2(tokens):
     left_node = parse_e3(tokens)
 
-    while tokens[0].token_type in [TokenType.T_MULT, TokenType.T_DIV]:
+    while tokens[0].token_type in [TokenType.T_MULT, TokenType.T_DIV, TokenType.T_MODULO]:
         node = tokens.pop(0)
         node.children.append(left_node)
         node.children.append(parse_e3(tokens))
diff --git a/graphviz.py b/graphviz.py
index a8bb018..3cf59a1 100644
--- a/graphviz.py
+++ b/graphviz.py
@@ -1,4 +1,4 @@
-import parser
+from arithmetic_expressions import parser
 import sys
 
 node_counter = 1
diff --git a/setup.py b/setup.py
new file mode 100644
index 0000000..c5ced58
--- /dev/null
+++ b/setup.py
@@ -0,0 +1,13 @@
+import setuptools
+
+with open("README.md", "r") as fh:
+    long_description = fh.read()
+
+setuptools.setup(
+    name="parser",
+    version="0.0.1",
+    long_description=long_description,
+    long_description_content_type="text/markdown",
+    packages=setuptools.find_packages(where="."),
+    python_requires=">=3.7",
+)
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/test.py b/tests/test.py
similarity index 81%
rename from test.py
rename to tests/test.py
index f45f9df..1c20a8f 100644
--- a/test.py
+++ b/tests/test.py
@@ -1,5 +1,4 @@
-import compute
-import parser
+from arithmetic_expressions import parser, compute
 
 
 def test_computation(inputstring, expected_output):
@@ -24,6 +23,11 @@ def test_computation(inputstring, expected_output):
 test_computation('2-(3*4+1)', -11)
 test_computation('2*(3*4+1)', 26)
 test_computation('8/((1+3)*2)', 1)
+test_computation('2%3', 2)
+test_computation('2%3+1', 3)
+test_computation('1+2%3', 3)
+test_computation('(1+2)%3', 0)
+test_computation('(1+2)%3', 0)
 
 try:
     test_computation('1+1)', 1)