diff --git a/.github/workflows/ompi_mpi4py.yaml b/.github/workflows/ompi_mpi4py.yaml
index f84306a7657..0e9f675023e 100644
--- a/.github/workflows/ompi_mpi4py.yaml
+++ b/.github/workflows/ompi_mpi4py.yaml
@@ -113,27 +113,27 @@ jobs:
         CFLAGS: "-O0"
 
     - name: Test mpi4py (singleton)
-      run:  python test/main.py -v -x test_doc
+      run:  python test/main.py -v -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
     - name: Test mpi4py (np=1)
-      run:  mpiexec -n 1 python test/main.py -v -x test_doc
+      run:  mpiexec -n 1 python test/main.py -v -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
     - name: Test mpi4py (np=2)
-      run:  mpiexec -n 2 python test/main.py -v -f -x test_doc
+      run:  mpiexec -n 2 python test/main.py -v -f -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
     - name: Test mpi4py (np=3)
-      run:  mpiexec -n 3 python test/main.py -v -f -x test_doc
+      run:  mpiexec -n 3 python test/main.py -v -f -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
     - name: Test mpi4py (np=4)
-      run:  mpiexec -n 4 python test/main.py -v -f -x test_doc
+      run:  mpiexec -n 4 python test/main.py -v -f -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
     - name: Test mpi4py (np=5)
-      run:  mpiexec -n 5 python test/main.py -v -f -x test_doc
+      run:  mpiexec -n 5 python test/main.py -v -f -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
 
@@ -151,7 +151,7 @@ jobs:
         echo LD_LIBRARY_PATH=/opt/ompi/lib >> $GITHUB_ENV
 
     - name: Test mpi4py (singleton)
-      run:  python test/main.py -v -x test_doc
+      run:  python test/main.py -v -x TestExcErrhandlerNull
       if:   ${{ true }}
       timeout-minutes: 10
 
diff --git a/docs/Makefile.am b/docs/Makefile.am
index f6993850939..7d5d315ea2b 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -179,6 +179,7 @@ OMPI_MAN3 = \
         MPI_Errhandler_set.3 \
         MPI_Error_class.3 \
         MPI_Error_string.3 \
+        MPI_Errors.3 \
         MPI_Exscan.3 \
         MPI_Exscan_init.3 \
         MPI_Fetch_and_op.3 \
diff --git a/docs/man-openmpi/man3/MPI_Errors.3.rst b/docs/man-openmpi/man3/MPI_Errors.3.rst
index bb8f99fcf97..539a7286844 100644
--- a/docs/man-openmpi/man3/MPI_Errors.3.rst
+++ b/docs/man-openmpi/man3/MPI_Errors.3.rst
@@ -343,6 +343,14 @@ Standard error return classes for Open MPI:
      - 78
      - Invalid session
 
+   * - MPI_ERR_VALUE_TOO_LARGE
+     - 79
+     - Value is too large to store.
+
+   * - MPI_ERR_ERRHANDLER
+     - 89
+     - Invalid error handler handle.
+
    * - MPI_ERR_LASTCODE
      - 93
      - Last error code.
diff --git a/ompi/errhandler/errcode.c b/ompi/errhandler/errcode.c
index 63b55be9fea..ea3fc8c2ab9 100644
--- a/ompi/errhandler/errcode.c
+++ b/ompi/errhandler/errcode.c
@@ -127,6 +127,7 @@ static ompi_mpi_errcode_t ompi_err_revoked;
 #endif
 static ompi_mpi_errcode_t ompi_err_session;
 static ompi_mpi_errcode_t ompi_err_value_too_large;
+static ompi_mpi_errcode_t ompi_err_errhandler;
 
 static void ompi_mpi_errcode_construct(ompi_mpi_errcode_t* errcode);
 static void ompi_mpi_errcode_destruct(ompi_mpi_errcode_t* errcode);
@@ -245,6 +246,7 @@ int ompi_mpi_errcode_init (void)
 #endif
     CONSTRUCT_ERRCODE( ompi_err_session,  MPI_ERR_SESSION,  "MPI_ERR_SESSION: Invalid session handle" );
     CONSTRUCT_ERRCODE( ompi_err_value_too_large,  MPI_ERR_VALUE_TOO_LARGE,  "MPI_ERR_VALUE_TOO_LARGE: Value is too large to store" );
+    CONSTRUCT_ERRCODE( ompi_err_errhandler,  MPI_ERR_ERRHANDLER,  "MPI_ERR_ERRHANDLER: Invalid error handler handle" );
 
     /* Per MPI-3 p353:27-32, MPI_LASTUSEDCODE must be >=
        MPI_ERR_LASTCODE.  So just start it as == MPI_ERR_LASTCODE. */
@@ -362,6 +364,7 @@ int ompi_mpi_errcode_finalize (void)
 #endif
     OBJ_DESTRUCT(&ompi_err_session);
     OBJ_DESTRUCT(&ompi_err_value_too_large);
+    OBJ_DESTRUCT(&ompi_err_errhandler);
     OBJ_DESTRUCT(&ompi_mpi_errcodes);
     ompi_mpi_errcode_lastpredefined = 0;
     opal_mutex_unlock(&errcode_lock);
diff --git a/ompi/include/mpi.h.in b/ompi/include/mpi.h.in
index e838fe66061..02a03a651eb 100644
--- a/ompi/include/mpi.h.in
+++ b/ompi/include/mpi.h.in
@@ -752,6 +752,7 @@ enum {
 #define MPI_ERR_REVOKED               77
 #define MPI_ERR_SESSION               78
 #define MPI_ERR_VALUE_TOO_LARGE       79
+#define MPI_ERR_ERRHANDLER            80
 
 /* Per MPI-3 p349 47, MPI_ERR_LASTCODE must be >= the last predefined
    MPI_ERR_<foo> code. Set the last code to allow some room for adding
diff --git a/ompi/include/mpif-values.py b/ompi/include/mpif-values.py
index f4537762a79..f871a2b4b65 100755
--- a/ompi/include/mpif-values.py
+++ b/ompi/include/mpif-values.py
@@ -295,6 +295,7 @@
     'MPI_T_ERR_INVALID': 72,
     'MPI_ERR_SESSION': 78,
     'MPI_ERR_VALUE_TOO_LARGE': 79,
+    'MPI_ERR_ERRHANDLER': 80,
     'MPI_ERR_LASTCODE': 92,
     'MPI_IDENT': 0,
     'MPI_CONGRUENT': 1,
diff --git a/ompi/mpi/c/comm_create_from_group.c.in b/ompi/mpi/c/comm_create_from_group.c.in
index 26e4049fac5..3b36446af40 100644
--- a/ompi/mpi/c/comm_create_from_group.c.in
+++ b/ompi/mpi/c/comm_create_from_group.c.in
@@ -51,7 +51,7 @@ PROTOTYPE ERROR_CLASS comm_create_from_group (GROUP group, STRING tag, INFO info
                     ( OMPI_ERRHANDLER_TYPE_COMM != errhandler->eh_mpi_object_type &&
                      OMPI_ERRHANDLER_TYPE_PREDEFINED != errhandler->eh_mpi_object_type) ) {
                return ompi_errhandler_invoke (NULL, MPI_COMM_NULL, OMPI_ERRHANDLER_TYPE_COMM,
-                                              MPI_ERR_ARG,FUNC_NAME);
+                                              MPI_ERR_ERRHANDLER,FUNC_NAME);
         }
 
         if (NULL == tag) {
diff --git a/ompi/mpi/c/comm_set_errhandler.c.in b/ompi/mpi/c/comm_set_errhandler.c.in
index 9cfabe8e856..4355d23c833 100644
--- a/ompi/mpi/c/comm_set_errhandler.c.in
+++ b/ompi/mpi/c/comm_set_errhandler.c.in
@@ -14,7 +14,7 @@
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2016-2017 Los Alamos National Security, LLC. All rights
  *                         reserved.
- * Copyright (c) 2024      Triad National Security, LLC. All rights
+ * Copyright (c) 2024-2025 Triad National Security, LLC. All rights
  *                         reserved.
  * $COPYRIGHT$
  *
@@ -51,7 +51,7 @@ PROTOTYPE ERROR_CLASS comm_set_errhandler(COMM comm, ERRHANDLER errhandler)
                    MPI_ERRHANDLER_NULL == errhandler ||
                    ( OMPI_ERRHANDLER_TYPE_COMM != errhandler->eh_mpi_object_type &&
                      OMPI_ERRHANDLER_TYPE_PREDEFINED != errhandler->eh_mpi_object_type) ) {
-            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG,
+            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ERRHANDLER,
                                           FUNC_NAME);
         }
     }
diff --git a/ompi/mpi/c/errhandler_c2f.c.in b/ompi/mpi/c/errhandler_c2f.c.in
index b563a49c333..e0f209510a0 100644
--- a/ompi/mpi/c/errhandler_c2f.c.in
+++ b/ompi/mpi/c/errhandler_c2f.c.in
@@ -35,7 +35,7 @@ PROTOTYPE FINT errhandler_c2f(ERRHANDLER errhandler)
   if (MPI_PARAM_CHECK) {
 	/* mapping an invalid handle to a null handle */
     if (NULL == errhandler) {
-        return OMPI_INT_2_FINT(-1);
+        return OMPI_INT_2_FINT(MPI_ERR_ERRHANDLER);
     }
   }
 
diff --git a/ompi/mpi/c/errhandler_free.c.in b/ompi/mpi/c/errhandler_free.c.in
index 8f888f1965e..6c9153de1d9 100644
--- a/ompi/mpi/c/errhandler_free.c.in
+++ b/ompi/mpi/c/errhandler_free.c.in
@@ -39,7 +39,7 @@ PROTOTYPE ERROR_CLASS errhandler_free(ERRHANDLER_OUT errhandler)
     if (NULL == errhandler ||
         (ompi_errhandler_is_intrinsic(*errhandler) &&
          1 == (*errhandler)->super.obj_reference_count)) {
-      return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_ARG,
+      return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_ERRHANDLER,
                                    "MPI_Errhandler_free");
     }
   }
diff --git a/ompi/mpi/c/file_set_errhandler.c.in b/ompi/mpi/c/file_set_errhandler.c.in
index 12edd9c65b2..36d9508f206 100644
--- a/ompi/mpi/c/file_set_errhandler.c.in
+++ b/ompi/mpi/c/file_set_errhandler.c.in
@@ -51,7 +51,7 @@ PROTOTYPE ERROR_CLASS file_set_errhandler(FILE file, ERRHANDLER errhandler)
                    MPI_ERRHANDLER_NULL == errhandler ||
                    (OMPI_ERRHANDLER_TYPE_FILE != errhandler->eh_mpi_object_type &&
 		    OMPI_ERRHANDLER_TYPE_PREDEFINED != errhandler->eh_mpi_object_type) ) {
-            return OMPI_ERRHANDLER_INVOKE(file, MPI_ERR_ARG, FUNC_NAME);
+            return OMPI_ERRHANDLER_INVOKE(file, MPI_ERR_ERRHANDLER, FUNC_NAME);
         }
     }
 
diff --git a/ompi/mpi/c/intercomm_create_from_groups.c.in b/ompi/mpi/c/intercomm_create_from_groups.c.in
index ac1b88f257c..aa868713cd8 100644
--- a/ompi/mpi/c/intercomm_create_from_groups.c.in
+++ b/ompi/mpi/c/intercomm_create_from_groups.c.in
@@ -55,7 +55,7 @@ PROTOTYPE ERROR_CLASS intercomm_create_from_groups (GROUP local_group, INT local
                     ( OMPI_ERRHANDLER_TYPE_COMM != errhandler->eh_mpi_object_type &&
                      OMPI_ERRHANDLER_TYPE_PREDEFINED != errhandler->eh_mpi_object_type) ) {
                return ompi_errhandler_invoke (NULL, MPI_COMM_NULL, OMPI_ERRHANDLER_TYPE_COMM,
-                                      MPI_ERR_ARG,FUNC_NAME);
+                                      MPI_ERR_ERRHANDLER,FUNC_NAME);
 
         }
 
diff --git a/ompi/mpi/c/session_init.c.in b/ompi/mpi/c/session_init.c.in
index bcc71c7eeb4..e113f3b142c 100644
--- a/ompi/mpi/c/session_init.c.in
+++ b/ompi/mpi/c/session_init.c.in
@@ -25,12 +25,19 @@ PROTOTYPE ERROR_CLASS session_init (INFO info, ERRHANDLER errhandler, SESSION_OU
     const char ts_level_multi[] = "MPI_THREAD_MULTIPLE";
 
     if ( MPI_PARAM_CHECK ) {
-        if (NULL == errhandler || NULL == session) {
-            return MPI_ERR_ARG;
+        if (NULL == errhandler) {
+            rc = MPI_ERR_ERRHANDLER;
+            goto fn_exit;
+        }
+
+        if (NULL == session) {
+            rc = MPI_ERR_ARG;
+            goto fn_exit;
         }
 
         if (NULL == info || ompi_info_is_freed (info)) {
-            return MPI_ERR_INFO;
+            rc = MPI_ERR_INFO;
+            goto fn_exit;
         }
     }
 
@@ -46,5 +53,6 @@ PROTOTYPE ERROR_CLASS session_init (INFO info, ERRHANDLER errhandler, SESSION_OU
 
     rc = ompi_mpi_instance_init (ts_level, &info->super, errhandler, session, 0, NULL);
     /* if an error occurred raise it on the null session */
+fn_exit:
     OMPI_ERRHANDLER_RETURN (rc, MPI_SESSION_NULL, rc, FUNC_NAME);
 }
diff --git a/ompi/mpi/c/session_set_errhandler.c.in b/ompi/mpi/c/session_set_errhandler.c.in
index a2ad8e36efe..1e500e90f90 100644
--- a/ompi/mpi/c/session_set_errhandler.c.in
+++ b/ompi/mpi/c/session_set_errhandler.c.in
@@ -43,7 +43,7 @@ PROTOTYPE ERROR_CLASS session_set_errhandler(SESSION session, ERRHANDLER errhand
                    MPI_ERRHANDLER_NULL == errhandler ||
                    ( OMPI_ERRHANDLER_TYPE_INSTANCE != errhandler->eh_mpi_object_type &&
                      OMPI_ERRHANDLER_TYPE_PREDEFINED != errhandler->eh_mpi_object_type) ) {
-            return OMPI_ERRHANDLER_INVOKE(session, MPI_ERR_ARG,
+            return OMPI_ERRHANDLER_INVOKE(session, MPI_ERR_ERRHANDLER,
                                           FUNC_NAME);
         }
     }
diff --git a/ompi/mpi/c/win_set_errhandler.c.in b/ompi/mpi/c/win_set_errhandler.c.in
index 80a71e34aad..2442cc75502 100644
--- a/ompi/mpi/c/win_set_errhandler.c.in
+++ b/ompi/mpi/c/win_set_errhandler.c.in
@@ -46,7 +46,7 @@ PROTOTYPE ERROR_CLASS win_set_errhandler(WIN win, ERRHANDLER errhandler)
                    MPI_ERRHANDLER_NULL == errhandler ||
                    (OMPI_ERRHANDLER_TYPE_WIN != errhandler->eh_mpi_object_type &&
                     OMPI_ERRHANDLER_TYPE_PREDEFINED != errhandler->eh_mpi_object_type) ) {
-            return OMPI_ERRHANDLER_INVOKE(win, MPI_ERR_ARG, FUNC_NAME);
+            return OMPI_ERRHANDLER_INVOKE(win, MPI_ERR_ERRHANDLER, FUNC_NAME);
         }
     }