diff --git a/changelog.d/7637.misc b/changelog.d/7637.misc
new file mode 100644
index 000000000..90d41fa77
--- /dev/null
+++ b/changelog.d/7637.misc
@@ -0,0 +1 @@
+Fix typos of `m.olm.curve25519-aes-sha2` and `m.megolm.v1.aes-sha2` in comments, test files.
\ No newline at end of file
diff --git a/synapse/rest/client/v2_alpha/keys.py b/synapse/rest/client/v2_alpha/keys.py
index 8f41a3edb..24bb09082 100644
--- a/synapse/rest/client/v2_alpha/keys.py
+++ b/synapse/rest/client/v2_alpha/keys.py
@@ -42,7 +42,7 @@ class KeyUploadServlet(RestServlet):
         "device_id": "<device_id>",
         "valid_until_ts": <millisecond_timestamp>,
         "algorithms": [
-          "m.olm.curve25519-aes-sha256",
+          "m.olm.curve25519-aes-sha2",
         ]
         "keys": {
           "<algorithm>:<device_id>": "<key_base64>",
@@ -124,7 +124,7 @@ class KeyQueryServlet(RestServlet):
             "device_id": "<device_id>", // Duplicated to be signed
             "valid_until_ts": <millisecond_timestamp>,
             "algorithms": [ // List of supported algorithms
-              "m.olm.curve25519-aes-sha256",
+              "m.olm.curve25519-aes-sha2",
             ],
             "keys": { // Must include a ed25519 signing key
               "<algorithm>:<key_id>": "<key_base64>",
@@ -285,8 +285,8 @@ class SignaturesUploadServlet(RestServlet):
           "user_id": "<user_id>",
           "device_id": "<device_id>",
           "algorithms": [
-            "m.olm.curve25519-aes-sha256",
-            "m.megolm.v1.aes-sha"
+            "m.olm.curve25519-aes-sha2",
+            "m.megolm.v1.aes-sha2"
           ],
           "keys": {
             "<algorithm>:<device_id>": "<key_base64>",
diff --git a/tests/federation/test_federation_sender.py b/tests/federation/test_federation_sender.py
index 33105576a..ff1253904 100644
--- a/tests/federation/test_federation_sender.py
+++ b/tests/federation/test_federation_sender.py
@@ -536,7 +536,7 @@ def build_device_dict(user_id: str, device_id: str, sk: SigningKey):
     return {
         "user_id": user_id,
         "device_id": device_id,
-        "algorithms": ["m.olm.curve25519-aes-sha256", "m.megolm.v1.aes-sha"],
+        "algorithms": ["m.olm.curve25519-aes-sha2", "m.megolm.v1.aes-sha2"],
         "keys": {
             "curve25519:" + device_id: "curve25519+key",
             key_id(sk): encode_pubkey(sk),
diff --git a/tests/handlers/test_e2e_keys.py b/tests/handlers/test_e2e_keys.py
index 854eb6c02..e1e144b2e 100644
--- a/tests/handlers/test_e2e_keys.py
+++ b/tests/handlers/test_e2e_keys.py
@@ -222,7 +222,7 @@ class E2eKeysHandlerTestCase(unittest.TestCase):
         device_key_1 = {
             "user_id": local_user,
             "device_id": "abc",
-            "algorithms": ["m.olm.curve25519-aes-sha256", "m.megolm.v1.aes-sha"],
+            "algorithms": ["m.olm.curve25519-aes-sha2", "m.megolm.v1.aes-sha2"],
             "keys": {
                 "ed25519:abc": "base64+ed25519+key",
                 "curve25519:abc": "base64+curve25519+key",
@@ -232,7 +232,7 @@ class E2eKeysHandlerTestCase(unittest.TestCase):
         device_key_2 = {
             "user_id": local_user,
             "device_id": "def",
-            "algorithms": ["m.olm.curve25519-aes-sha256", "m.megolm.v1.aes-sha"],
+            "algorithms": ["m.olm.curve25519-aes-sha2", "m.megolm.v1.aes-sha2"],
             "keys": {
                 "ed25519:def": "base64+ed25519+key",
                 "curve25519:def": "base64+curve25519+key",
@@ -315,7 +315,7 @@ class E2eKeysHandlerTestCase(unittest.TestCase):
         device_key = {
             "user_id": local_user,
             "device_id": device_id,
-            "algorithms": ["m.olm.curve25519-aes-sha256", "m.megolm.v1.aes-sha"],
+            "algorithms": ["m.olm.curve25519-aes-sha2", "m.megolm.v1.aes-sha2"],
             "keys": {"curve25519:xyz": "curve25519+key", "ed25519:xyz": device_pubkey},
             "signatures": {local_user: {"ed25519:xyz": "something"}},
         }
@@ -391,8 +391,8 @@ class E2eKeysHandlerTestCase(unittest.TestCase):
                         "user_id": local_user,
                         "device_id": device_id,
                         "algorithms": [
-                            "m.olm.curve25519-aes-sha256",
-                            "m.megolm.v1.aes-sha",
+                            "m.olm.curve25519-aes-sha2",
+                            "m.megolm.v1.aes-sha2",
                         ],
                         "keys": {
                             "curve25519:xyz": "curve25519+key",