diff --git a/src/outbound_group_session.c b/src/outbound_group_session.c
index 6acad5a..4a251d0 100644
--- a/src/outbound_group_session.c
+++ b/src/outbound_group_session.c
@@ -103,12 +103,21 @@ size_t olm_pickle_outbound_group_session(
         return (size_t)-1;
     }
 
+#ifndef OLM_FUZZING
     pos = _olm_enc_output_pos(pickled, raw_length);
+#else
+    pos = pickled;
+#endif
+
     pos = _olm_pickle_uint32(pos, PICKLE_VERSION);
     pos = megolm_pickle(&(session->ratchet), pos);
     pos = _olm_pickle_ed25519_key_pair(pos, &(session->signing_key));
 
+#ifndef OLM_FUZZING
     return _olm_enc_output(key, key_length, pickled, raw_length);
+#else
+    return raw_length;
+#endif
 }
 
 size_t olm_unpickle_outbound_group_session(
@@ -120,9 +129,14 @@ size_t olm_unpickle_outbound_group_session(
     const uint8_t *end;
     uint32_t pickle_version;
 
+#ifndef OLM_FUZZING
     size_t raw_length = _olm_enc_input(
         key, key_length, pickled, pickled_length, &(session->last_error)
     );
+#else
+    size_t raw_length = pickled_length;
+#endif
+
     if (raw_length == (size_t)-1) {
         return raw_length;
     }