diff --git a/.circleci/config.yml b/.circleci/config.yml
index 19ab1543a..60d26e896 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -112,6 +112,15 @@ jobs:
       - run:
           name: Check table of contents
           command: sudo npm install -g doctoc && make check_toc
+  codespell:
+    docker:
+      - image: circleci/python:3.6
+    working_directory: ~/specs-repo
+    steps:
+      - checkout
+      - run:
+          name: Check codespell
+          command: pip install codespell --user &&  make codespell
   lint:
     docker:
       - image: circleci/python:3.6
@@ -158,6 +167,7 @@ workflows:
           requires:
             - install_pyspec_test
       - table_of_contents
+      - codespell
       - lint:
           requires:
             - test
diff --git a/Makefile b/Makefile
index 2cdb1021f..2b165ad7d 100644
--- a/Makefile
+++ b/Makefile
@@ -77,6 +77,9 @@ check_toc: $(MARKDOWN_FILES:=.toc)
 	diff -q $* $*.tmp && \
 	rm $*.tmp
 
+codespell:
+	codespell . --skip ./.git -I .codespell-whitelist
+
 lint: $(PY_SPEC_ALL_TARGETS)
 	cd $(PY_SPEC_DIR); . venv/bin/activate; \
 	flake8  --ignore=E252,W504,W503 --max-line-length=120 ./eth2spec \
diff --git a/scripts/build_spec.py b/scripts/build_spec.py
index cca5a1bf9..d5689b082 100644
--- a/scripts/build_spec.py
+++ b/scripts/build_spec.py
@@ -252,7 +252,7 @@ def combine_ssz_objects(old_objects: Dict[str, str], new_objects: Dict[str, str]
     return old_objects
 
 
-# inserts are handeled the same way as functions
+# inserts are handled the same way as functions
 combine_inserts = combine_functions
 
 
diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index e7c62d342..ab1ea2c08 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -560,7 +560,7 @@ def int_to_bytes(n: uint64, length: uint64) -> bytes:
 ```python
 def bytes_to_int(data: bytes) -> uint64:
     """
-    Return the integer deserialization of ``data`` intepreted as ``ENDIANNESS``-endian.
+    Return the integer deserialization of ``data`` interpreted as ``ENDIANNESS``-endian.
     """
     return int.from_bytes(data, ENDIANNESS)
 ```
diff --git a/specs/test_formats/ssz_generic/README.md b/specs/test_formats/ssz_generic/README.md
index b6faa04af..68bdbc15f 100644
--- a/specs/test_formats/ssz_generic/README.md
+++ b/specs/test_formats/ssz_generic/README.md
@@ -150,7 +150,7 @@ Template:
 
 Data:
 
-{container name}: Any of the container names listed below (exluding the `(Container)` python super type)
+{container name}: Any of the container names listed below (excluding the `(Container)` python super type)
 ```
 
 ```python
diff --git a/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py b/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py
index 98a6e25e5..dba48ca64 100644
--- a/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py
+++ b/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py
@@ -262,7 +262,7 @@ def test_att1_duplicate_index_normal_signed(spec, state):
     indices.pop(1)  # remove an index, make room for the additional duplicate index.
     attester_slashing.attestation_1.attesting_indices = sorted(indices)
 
-    # sign it, the signature will be valid for a single occurence. If the transition accidentally ignores the duplicate.
+    # The signature will be valid for a single occurrence. If the transition accidentally ignores the duplicate.
     sign_indexed_attestation(spec, state, attester_slashing.attestation_1)
 
     indices.append(indices[0])  # add one of the indices a second time
@@ -282,7 +282,7 @@ def test_att2_duplicate_index_normal_signed(spec, state):
     indices.pop(2)  # remove an index, make room for the additional duplicate index.
     attester_slashing.attestation_2.attesting_indices = sorted(indices)
 
-    # sign it, the signature will be valid for a single occurence. If the transition accidentally ignores the duplicate.
+    # The signature will be valid for a single occurrence. If the transition accidentally ignores the duplicate.
     sign_indexed_attestation(spec, state, attester_slashing.attestation_2)
 
     indices.append(indices[1])  # add one of the indices a second time
diff --git a/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py b/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py
index 7d844b63b..b4fc46b7d 100644
--- a/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py
+++ b/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py
@@ -155,7 +155,7 @@ def test_duplicate_attestation(spec, state):
     next_epoch(spec, single_state)
     next_epoch(spec, dup_state)
 
-    # Run non-duplicate inclusion rewards for comparision. Do not yield test vectors
+    # Run non-duplicate inclusion rewards for comparison. Do not yield test vectors
     for _ in run_process_rewards_and_penalties(spec, single_state):
         pass