diff --git a/doc/APIreference/functions.rst b/doc/APIreference/functions.rst
index 02e40dc8..c625ab2e 100644
--- a/doc/APIreference/functions.rst
+++ b/doc/APIreference/functions.rst
@@ -1342,8 +1342,6 @@ Set default options for length range computation.
 
 Set solver parameters to default values.
 
-*Nullable:* ``solref``, ``solimp``
-
 .. _mj_defaultOption:
 
 `mj_defaultOption <#mj_defaultOption>`__
@@ -1371,8 +1369,6 @@ Set visual options to default values.
 
 Copy mjModel, allocate new if dest is NULL.
 
-*Nullable:* ``dest``
-
 .. _mj_saveModel:
 
 `mj_saveModel <#mj_saveModel>`__
diff --git a/include/mujoco/mujoco.h b/include/mujoco/mujoco.h
index a7b100c1..677d280a 100644
--- a/include/mujoco/mujoco.h
+++ b/include/mujoco/mujoco.h
@@ -166,7 +166,6 @@ MJAPI void mj_inverseSkip(const mjModel* m, mjData* d, int skipstage, int skipse
 MJAPI void mj_defaultLROpt(mjLROpt* opt);
 
 // Set solver parameters to default values.
-// Nullable: solref, solimp
 MJAPI void mj_defaultSolRefImp(mjtNum* solref, mjtNum* solimp);
 
 // Set physics options to default values.
@@ -176,7 +175,6 @@ MJAPI void mj_defaultOption(mjOption* opt);
 MJAPI void mj_defaultVisual(mjVisual* vis);
 
 // Copy mjModel, allocate new if dest is NULL.
-// Nullable: dest
 MJAPI mjModel* mj_copyModel(mjModel* dest, const mjModel* src);
 
 // Save model to binary MJB file or memory buffer; buffer has precedence when given.
diff --git a/python/mujoco/introspect/functions.py b/python/mujoco/introspect/functions.py
index 050a17c8..e925870b 100644
--- a/python/mujoco/introspect/functions.py
+++ b/python/mujoco/introspect/functions.py
@@ -592,14 +592,12 @@ FUNCTIONS: Mapping[str, FunctionDecl] = dict([
                  type=PointerType(
                      inner_type=ValueType(name='mjtNum'),
                  ),
-                 nullable=True,
              ),
              FunctionParameterDecl(
                  name='solimp',
                  type=PointerType(
                      inner_type=ValueType(name='mjtNum'),
                  ),
-                 nullable=True,
              ),
          ),
          doc='Set solver parameters to default values.',
@@ -644,7 +642,6 @@ FUNCTIONS: Mapping[str, FunctionDecl] = dict([
                  type=PointerType(
                      inner_type=ValueType(name='mjModel'),
                  ),
-                 nullable=True,
              ),
              FunctionParameterDecl(
                  name='src',