diff --git a/doc/changelog.rst b/doc/changelog.rst
index 91205484..349e03c5 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -10,6 +10,9 @@ Python bindings
 
 - Fixed IPython history corruption when using ``launch_repl``. The ``launch_repl`` function now provides seamless
   continuation of an IPython interactive shell session, and is no longer considered experimental feature.
+- Remove ``efc_`` fields from joint indexers. Since the introduction of arena memory, these fields now have dynamic
+  sizes that change between time steps depending on the number of active constraints, breaking strict correspondence
+  between joints and `efc_` rows.
 
 
 Version 2.3.2 (February 7, 2023)
diff --git a/python/mujoco/indexer_xmacro.h b/python/mujoco/indexer_xmacro.h
index ed6dfba0..bc462853 100644
--- a/python/mujoco/indexer_xmacro.h
+++ b/python/mujoco/indexer_xmacro.h
@@ -356,11 +356,6 @@
   X( mjtNum, , cdof,            nv,   6           ) \
   X( mjtNum, , qLDiagInv,       nv,   1           ) \
   X( mjtNum, , qLDiagSqrtInv,   nv,   1           ) \
-  X( int,    , efc_JT_rownnz,   nv,   1           ) \
-  X( int,    , efc_JT_rowadr,   nv,   1           ) \
-  X( int,    , efc_JT_rowsuper, nv,   1           ) \
-  X( int,    , efc_JT_colind,   nv,   MJ_M(njmax) ) \
-  X( mjtNum, , efc_JT,          nv,   MJ_M(njmax) ) \
   X( mjtNum, , cdof_dot,        nv,   6           ) \
   X( mjtNum, , qfrc_bias,       nv,   1           ) \
   X( mjtNum, , qfrc_passive,    nv,   1           ) \