diff --git a/cifti/CMakeLists.txt b/cifti/CMakeLists.txt
index d19b7524..9e539c20 100644
--- a/cifti/CMakeLists.txt
+++ b/cifti/CMakeLists.txt
@@ -26,3 +26,19 @@ if(NIFTI_BUILD_APPLICATIONS)
   install_nifti_target(${NIFTI_PACKAGE_PREFIX}afni_xml_tool)
   install_nifti_target(${NIFTI_PACKAGE_PREFIX}cifti_tool)
 endif()
+
+if(NIFTI_BUILD_TESTING AND NIFTI_BUILD_APPLICATIONS)
+  set(TEST_PREFIX "${NIFTI_PACKAGE_PREFIX}cifti")
+  # An unrecognized MatrixIndicesMap child is skipped, not dispatched on.
+  add_test( NAME ${TEST_PREFIX}_mim_summary_unknown_child
+            COMMAND $<TARGET_FILE:${NIFTI_PACKAGE_PREFIX}cifti_tool>
+                    -as_cext -eval_cext -eval_type show_summary
+                    -input ${CMAKE_CURRENT_LIST_DIR}/testdata/mim_unknown_child.xml )
+  # A recognized child is still displayed.
+  add_test( NAME ${TEST_PREFIX}_mim_summary_known_child
+            COMMAND $<TARGET_FILE:${NIFTI_PACKAGE_PREFIX}cifti_tool>
+                    -as_cext -eval_cext -eval_type show_summary
+                    -input ${CMAKE_CURRENT_LIST_DIR}/testdata/mim_known_child.xml )
+  set_tests_properties( ${TEST_PREFIX}_mim_summary_known_child
+                        PROPERTIES PASS_REGULAR_EXPRESSION "BrainModel" )
+endif()
diff --git a/cifti/afni_xml_io.c b/cifti/afni_xml_io.c
index a59f5c3e..a06229e4 100644
--- a/cifti/afni_xml_io.c
+++ b/cifti/afni_xml_io.c
@@ -263,7 +263,8 @@ int axio_show_mim_summary(FILE * fp, const char * mesg, afni_xml_t * ax, int ver
 
       for( kid=0; kid<xt->nchild; kid++ ) {
          mind = get_map_index(xt->xchild[kid]);
-         if( kid >= 0 ) MIM_disp_funcs[mind](ofp, xt->xchild[kid], verb);
+         /* get_map_index() returns -1 for an unrecognized element name */
+         if( mind >= 0 ) MIM_disp_funcs[mind](ofp, xt->xchild[kid], verb);
       }
    }
 
diff --git a/cifti/cifti_tool.c b/cifti/cifti_tool.c
index 488b70fb..b895c09f 100644
--- a/cifti/cifti_tool.c
+++ b/cifti/cifti_tool.c
@@ -193,6 +193,9 @@ int process(opts_t * opts)
    if( opts->disp_cext ) disp_cifti_extension(nim, opts);
    if( opts->eval_cext ) eval_cifti_extension(ax, opts);
 
+   axml_free_xml_t(ax);
+   nifti_image_free(nim);
+
    return 0;
 }
 
diff --git a/cifti/testdata/mim_known_child.xml b/cifti/testdata/mim_known_child.xml
new file mode 100644
index 00000000..30eecbdf
--- /dev/null
+++ b/cifti/testdata/mim_known_child.xml
@@ -0,0 +1,7 @@
+<CIFTI Version="2">
+  <Matrix>
+    <MatrixIndicesMap AppliesToMatrixDimension="0" IndicesMapToDataType="CIFTI_INDEX_TYPE_BRAIN_MODELS">
+      <BrainModel IndexOffset="0" IndexCount="2" ModelType="CIFTI_MODEL_TYPE_VOXELS" BrainStructure="CIFTI_STRUCTURE_CORTEX_LEFT"/>
+    </MatrixIndicesMap>
+  </Matrix>
+</CIFTI>
diff --git a/cifti/testdata/mim_unknown_child.xml b/cifti/testdata/mim_unknown_child.xml
new file mode 100644
index 00000000..83c64772
--- /dev/null
+++ b/cifti/testdata/mim_unknown_child.xml
@@ -0,0 +1,7 @@
+<CIFTI Version="2">
+  <Matrix>
+    <MatrixIndicesMap AppliesToMatrixDimension="0" IndicesMapToDataType="CIFTI_INDEX_TYPE_BRAIN_MODELS">
+      <UnrecognizedElement/>
+    </MatrixIndicesMap>
+  </Matrix>
+</CIFTI>