diff --git a/src/pkcs11/pkcs11-session.c b/src/pkcs11/pkcs11-session.c
index 00ee05fc..1732353b 100644
--- a/src/pkcs11/pkcs11-session.c
+++ b/src/pkcs11/pkcs11-session.c
@@ -192,7 +192,56 @@ out:
 CK_RV C_SessionCancel(CK_SESSION_HANDLE hSession,  /* the session's handle */
 		      CK_FLAGS flags)      /* flags control which sessions are cancelled */
 {
-	return CKR_FUNCTION_NOT_SUPPORTED;
+	struct sc_pkcs11_session *session;
+	CK_RV rv;
+
+	rv = sc_pkcs11_lock();
+	if (rv != CKR_OK)
+		return rv;
+
+	rv = get_session(hSession, &session);
+	if (rv != CKR_OK)
+		goto out;
+
+	/* Ignore return value of the cancel operation as it is valid to
+	 * cancel not started operation and it can not fail for other reasons */
+	if (flags & CKF_ENCRYPT) {
+		 /* unused */
+	}
+	if (flags & CKF_DECRYPT) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_DECRYPT);
+	}
+	if (flags & CKF_DIGEST) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_DIGEST);
+	}
+	if (flags & CKF_SIGN) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_SIGN);
+	}
+	if (flags & CKF_SIGN_RECOVER) {
+		/* unused */
+	}
+	if (flags & CKF_VERIFY) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_VERIFY);
+	}
+	if (flags & CKF_VERIFY_RECOVER) {
+		/* unused */
+	}
+	if (flags & CKF_GENERATE || flags & CKF_GENERATE_KEY_PAIR) {
+		/* unused */
+	}
+	if (flags & CKF_WRAP) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_WRAP);
+	}
+	if (flags & CKF_UNWRAP) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_UNWRAP);
+	}
+	if (flags & CKF_DERIVE) {
+		session_stop_operation(session, SC_PKCS11_OPERATION_DERIVE);
+	}
+
+out:
+	sc_pkcs11_unlock();
+	return rv;
 }
 
 CK_RV C_GetSessionInfo(CK_SESSION_HANDLE hSession,	/* the session's handle */