diff --git a/core/.changelog.d/4093.changed b/core/.changelog.d/4093.changed
new file mode 100644
index 0000000000..ab2575938f
--- /dev/null
+++ b/core/.changelog.d/4093.changed
@@ -0,0 +1 @@
+Changed prefix of public key returned by `get_ecdh_session_key` for curve25519.
diff --git a/core/src/apps/misc/get_ecdh_session_key.py b/core/src/apps/misc/get_ecdh_session_key.py
index 1aacc16725..68b55baed1 100644
--- a/core/src/apps/misc/get_ecdh_session_key.py
+++ b/core/src/apps/misc/get_ecdh_session_key.py
@@ -46,12 +46,10 @@ async def get_ecdh_session_key(msg: GetECDHSessionKey) -> ECDHSessionKey:
         from trezor.crypto.curve import secp256k1
 
         session_key = secp256k1.multiply(node.private_key(), peer_public_key)
-        public_key = node.public_key()
     elif curve_name == "nist256p1":
         from trezor.crypto.curve import nist256p1
 
         session_key = nist256p1.multiply(node.private_key(), peer_public_key)
-        public_key = node.public_key()
     elif curve_name == "curve25519":
         from trezor.crypto.curve import curve25519
 
@@ -60,9 +58,8 @@ async def get_ecdh_session_key(msg: GetECDHSessionKey) -> ECDHSessionKey:
         session_key = b"\x04" + curve25519.multiply(
             node.private_key(), peer_public_key[1:]
         )
-        public_key = b"\x01" + node.public_key()[1:]
     else:
         raise DataError("Unsupported curve for ECDH: " + curve_name)
     # END ecdh
 
-    return ECDHSessionKey(session_key=session_key, public_key=public_key)
+    return ECDHSessionKey(session_key=session_key, public_key=node.public_key())
diff --git a/legacy/firmware/.changelog.d/4093.changed b/legacy/firmware/.changelog.d/4093.changed
new file mode 100644
index 0000000000..ab2575938f
--- /dev/null
+++ b/legacy/firmware/.changelog.d/4093.changed
@@ -0,0 +1 @@
+Changed prefix of public key returned by `get_ecdh_session_key` for curve25519.
diff --git a/legacy/firmware/fsm_msg_crypto.h b/legacy/firmware/fsm_msg_crypto.h
index 5712371709..7ddaec6c48 100644
--- a/legacy/firmware/fsm_msg_crypto.h
+++ b/legacy/firmware/fsm_msg_crypto.h
@@ -221,9 +221,6 @@ void fsm_msgGetECDHSessionKey(const GetECDHSessionKey *msg) {
       return;
     }
     memcpy(resp->public_key.bytes, node->public_key, 33);
-    if (strcmp(curve, CURVE25519_NAME) == 0) {
-      resp->public_key.bytes[0] = 0x01;
-    }
     resp->public_key.size = 33;
     resp->has_public_key = true;
     msg_write(MessageType_MessageType_ECDHSessionKey, resp);
diff --git a/tests/device_tests/misc/test_msg_getecdhsessionkey.py b/tests/device_tests/misc/test_msg_getecdhsessionkey.py
index f09ff530c0..8c38f612b1 100644
--- a/tests/device_tests/misc/test_msg_getecdhsessionkey.py
+++ b/tests/device_tests/misc/test_msg_getecdhsessionkey.py
@@ -84,5 +84,5 @@ def test_ecdh(client: Client):
     )
     assert (
         result.public_key.hex()
-        == "019753a0738c55c7ba7c17dd4a9a975ce9b0d2b62e8a1ecef4a76767fad99d3c71"
+        == "009753a0738c55c7ba7c17dd4a9a975ce9b0d2b62e8a1ecef4a76767fad99d3c71"
     )