diff --git a/cmake/Modules/Packages/MDI.cmake b/cmake/Modules/Packages/MDI.cmake
index c7ef6130b8..1eec53db37 100644
--- a/cmake/Modules/Packages/MDI.cmake
+++ b/cmake/Modules/Packages/MDI.cmake
@@ -8,8 +8,8 @@ option(DOWNLOAD_MDI "Download and compile the MDI library instead of using an al
 
 if(DOWNLOAD_MDI)
   message(STATUS "MDI download requested - we will build our own")
-  set(MDI_URL "https://github.com/MolSSI-MDI/MDI_Library/archive/v1.3.0.tar.gz" CACHE STRING "URL for MDI tarball")
-  set(MDI_MD5 "8a8da217148bd9b700083b67d795af5e" CACHE STRING "MD5 checksum for MDI tarball")
+  set(MDI_URL "https://github.com/MolSSI-MDI/MDI_Library/archive/v1.3.2.tar.gz" CACHE STRING "URL for MDI tarball")
+  set(MDI_MD5 "836f5da400d8cff0f0e4435640f9454f" CACHE STRING "MD5 checksum for MDI tarball")
   mark_as_advanced(MDI_URL)
   mark_as_advanced(MDI_MD5)
   enable_language(C)
diff --git a/examples/mdi/in.aimd.driver.plugin b/examples/mdi/in.aimd.driver.plugin
index 858e42e2bd..d8c7fdde62 100644
--- a/examples/mdi/in.aimd.driver.plugin
+++ b/examples/mdi/in.aimd.driver.plugin
@@ -23,7 +23,7 @@ fix		1 all nve
 # NPT
 #fix             1 all npt temp 1.0 1.0 0.1 iso 1.0 1.0 1.0
 
-fix             2 all mdi/aimd plugin
+fix             2 all mdi/aimd
 fix_modify      2 energy yes virial yes
 
 thermo_style    custom step temp pe etotal press vol
diff --git a/examples/mdi/sequence_driver.py b/examples/mdi/sequence_driver.py
index ad1633ba2c..f15b2d4921 100644
--- a/examples/mdi/sequence_driver.py
+++ b/examples/mdi/sequence_driver.py
@@ -286,18 +286,15 @@ while iarg < narg:
 
 if not mdiarg: error()
 
+mdi.MDI_Init(mdiarg)
+
 # LAMMPS engine is a stand-alone code
 # world = MPI communicator for just this driver
 # invoke perform_tasks() directly
 
 if not plugin:
-  mdi.MDI_Init(mdiarg)
   world = mdi.MDI_MPI_get_world_comm()
-
-  # connect to engine
-
   mdicomm = mdi.MDI_Accept_Communicator()
-
   perform_tasks(world,mdicomm,None)
 
 # LAMMPS engine is a plugin library
@@ -305,7 +302,6 @@ if not plugin:
 # MDI will call back to perform_tasks()
 
 if plugin:
-  mdi.MDI_Init(mdiarg)
   world = MPI.COMM_WORLD
   plugin_args += " -mdi \"-role ENGINE -name lammps -method LINK\""
   mdi.MDI_Launch_plugin(plugin,plugin_args,world,perform_tasks,None)
diff --git a/lib/mdi/Install.py b/lib/mdi/Install.py
index 7f8cc91cd0..a439da34d2 100644
--- a/lib/mdi/Install.py
+++ b/lib/mdi/Install.py
@@ -34,12 +34,12 @@ make lib-meam args="-m ifort"   # build MEAM lib with custom Makefile.ifort (usi
 
 # settings
 
-version = "1.3.0"
+version = "1.3.2"
 url = "https://github.com/MolSSI-MDI/MDI_Library/archive/v%s.tar.gz" % version
 
 # known checksums for different MDI versions. used to validate the download.
 checksums = { \
-              '1.3.0' : '8a8da217148bd9b700083b67d795af5e', \
+              '1.3.2' : '836f5da400d8cff0f0e4435640f9454f', \
               }
 
 # print error message or help
diff --git a/src/MDI/fix_mdi_aimd.cpp b/src/MDI/fix_mdi_aimd.cpp
index 52df86e3e0..c878d183d3 100644
--- a/src/MDI/fix_mdi_aimd.cpp
+++ b/src/MDI/fix_mdi_aimd.cpp
@@ -29,7 +29,7 @@ enum { NATIVE, REAL, METAL };    // LAMMPS units which MDI supports
 
 FixMDIAimd::FixMDIAimd(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
 {
-  if (narg > 4) error->all(FLERR, "Illegal fix mdi/aimd command");
+  if (narg != 3) error->all(FLERR, "Illegal fix mdi/aimd command");
 
   scalar_flag = 1;
   global_freq = 1;
@@ -38,16 +38,6 @@ FixMDIAimd::FixMDIAimd(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
   virial_global_flag = 1;
   thermo_energy = thermo_virial = 1;
 
-  // check for plugin arg
-
-  plugin = 0;
-  if (narg == 4) {
-    if (strcmp(arg[3], "plugin") == 0)
-      plugin = 1;
-    else
-      error->all(FLERR, "Illegal fix mdi/aimd command");
-  }
-
   // check requirements for LAMMPS to work with MDI as an engine
 
   if (atom->tag_enable == 0) error->all(FLERR, "Cannot use MDI engine without atom IDs");
@@ -62,6 +52,11 @@ FixMDIAimd::FixMDIAimd(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
   if (role != MDI_DRIVER)
     error->all(FLERR, "Must invoke LAMMPS as an MDI driver to use fix mdi/aimd");
 
+  // mdicomm will be one-time initialized in init()
+  // cannot be done here for a plugin library, b/c mdi plugin command is later
+
+  mdicomm = MDI_COMM_NULL;
+
   // storage for all atoms
 
   buf3 = buf3all = nullptr;
@@ -78,13 +73,6 @@ FixMDIAimd::FixMDIAimd(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
 
   unit_conversions();
 
-  // connect to MDI engine, only if engine is stand-alone code
-
-  if (!plugin) {
-    MDI_Accept_communicator(&mdicomm);
-    if (mdicomm <= 0) error->all(FLERR, "Unable to connect to MDI engine");
-  }
-
   nprocs = comm->nprocs;
 }
 
@@ -92,7 +80,8 @@ FixMDIAimd::FixMDIAimd(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
 
 FixMDIAimd::~FixMDIAimd()
 {
-  // send exit command to engine, only if engine is stand-alone code
+  // send exit command to engine if it is a stand-alone code
+  // for plugin, this happens in MDIPlugin::plugin_wrapper()
 
   if (!plugin) {
     int ierr = MDI_Send_command("EXIT", mdicomm);
@@ -118,6 +107,30 @@ int FixMDIAimd::setmask()
 
 /* ---------------------------------------------------------------------- */
 
+void FixMDIAimd::init()
+{
+  if (mdicomm != MDI_COMM_NULL) return;
+
+  // one-time auto-detect whether engine is stand-alone code or plugin library
+  // also initializes mdicomm
+  // plugin = 0/1 for engine = stand-alone code vs plugin library
+
+  MDI_Get_communicator(&mdicomm, 0);
+
+  if (mdicomm == MDI_COMM_NULL) {
+    plugin = 0;
+    MDI_Accept_communicator(&mdicomm);
+    if (mdicomm == MDI_COMM_NULL) error->all(FLERR, "MDI unable to connect to stand-alone engine");
+  } else {
+    plugin = 1;
+    int method;
+    MDI_Get_method(&method, mdicomm);
+    if (method != MDI_PLUGIN) error->all(FLERR, "MDI internal error for plugin engine");
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
 void FixMDIAimd::setup(int vflag)
 {
   post_force(vflag);
diff --git a/src/MDI/fix_mdi_aimd.h b/src/MDI/fix_mdi_aimd.h
index 6ca886794f..7d408b414f 100644
--- a/src/MDI/fix_mdi_aimd.h
+++ b/src/MDI/fix_mdi_aimd.h
@@ -27,14 +27,11 @@ namespace LAMMPS_NS {
 
 class FixMDIAimd : public Fix {
  public:
-  // MDI communicator, public so that LAMMPS can work with a plugin
-
-  MDI_Comm mdicomm;
-
   FixMDIAimd(class LAMMPS *, int, char **);
   ~FixMDIAimd();
   int setmask();
 
+  void init();
   void setup(int);
   void setup_pre_reverse(int, int);
   void pre_reverse(int, int);
@@ -46,6 +43,8 @@ class FixMDIAimd : public Fix {
   int nprocs;
   int plugin;
 
+  MDI_Comm mdicomm;
+
   int eflag_caller;
   double engine_energy;
   int lmpunits;
diff --git a/src/MDI/mdi_engine.cpp b/src/MDI/mdi_engine.cpp
index 8408b2dd49..f2b96cb69a 100644
--- a/src/MDI/mdi_engine.cpp
+++ b/src/MDI/mdi_engine.cpp
@@ -601,7 +601,8 @@ void MDIEngine::mdi_md()
   // delete the instance before this method returns
 
   modify->add_fix("MDI_ENGINE_INTERNAL all MDI/ENGINE");
-  FixMDIEngine *mdi_fix = dynamic_cast<FixMDIEngine *>( modify->get_fix_by_id("MDI_ENGINE_INTERNAL"));
+  FixMDIEngine *mdi_fix =
+      dynamic_cast<FixMDIEngine *>(modify->get_fix_by_id("MDI_ENGINE_INTERNAL"));
   mdi_fix->mdi_engine = this;
 
   // initialize LAMMPS and setup() the simulation
@@ -723,7 +724,8 @@ void MDIEngine::mdi_optg()
   // delete the instance before this method returns
 
   modify->add_fix("MDI_ENGINE_INTERNAL all MDI/ENGINE");
-  FixMDIEngine *mdi_fix = dynamic_cast<FixMDIEngine *>( modify->get_fix_by_id("MDI_ENGINE_INTERNAL"));
+  FixMDIEngine *mdi_fix =
+      dynamic_cast<FixMDIEngine *>(modify->get_fix_by_id("MDI_ENGINE_INTERNAL"));
   mdi_fix->mdi_engine = this;
 
   // initialize LAMMPS and setup() the simulation
@@ -956,7 +958,8 @@ void MDIEngine::create_system()
   // optionally set charges if specified by ">CHARGES"
 
   if (flag_velocities)
-    lammps_create_atoms(lmp, sys_natoms, nullptr, sys_types, sys_coords, sys_velocities, nullptr, 1);
+    lammps_create_atoms(lmp, sys_natoms, nullptr, sys_types, sys_coords, sys_velocities, nullptr,
+                        1);
   else
     lammps_create_atoms(lmp, sys_natoms, nullptr, sys_types, sys_coords, nullptr, nullptr, 1);
 
diff --git a/src/MDI/mdi_plugin.cpp b/src/MDI/mdi_plugin.cpp
index 99549a621f..3c8e38481d 100644
--- a/src/MDI/mdi_plugin.cpp
+++ b/src/MDI/mdi_plugin.cpp
@@ -92,11 +92,6 @@ MDIPlugin::MDIPlugin(LAMMPS *_lmp, int narg, char **arg) : Pointers(_lmp)
     strcat(plugin_args, extra_arg);
   }
 
-  // find FixMDIAimd instance so can reset its mdicomm
-  // NOTE: this is a kludge - need better way to handle this
-
-  fixptr = modify->get_fix_by_style("mdi/aimd")[0];
-
   // launch the MDI plugin library
   // path for lib was specified in -mdi command-line arg when LAMMPS started
   // this calls back to plugin_wrapper, which must issue MDI EXIT at end
@@ -108,8 +103,7 @@ MDIPlugin::MDIPlugin(LAMMPS *_lmp, int narg, char **arg) : Pointers(_lmp)
 
 /* ----------------------------------------------------------------------
    callback function from MDI_Launch_plugin()
-   this function must wrap entire interaction of LAMMPS as a driver
-     with the plugin
+   this function wraps entire interaction of LAMMPS driver with the plugin
 ---------------------------------------------------------------------- */
 
 int MDIPlugin::plugin_wrapper(void * /*pmpicomm*/, MDI_Comm mdicomm, void *vptr)
@@ -118,11 +112,6 @@ int MDIPlugin::plugin_wrapper(void * /*pmpicomm*/, MDI_Comm mdicomm, void *vptr)
   LAMMPS *lammps = ptr->lmp;
   char *lammps_command = ptr->lammps_command;
 
-  // set FixMDIAimd mdicomm to driver's mdicomm passed to this callback
-
-  auto aimdptr = dynamic_cast<FixMDIAimd *> (ptr->fixptr);
-  aimdptr->mdicomm = mdicomm;
-
   // invoke the specified LAMMPS command
   // that operation will issue MDI commands to the plugin engine
 
diff --git a/src/MDI/mdi_plugin.h b/src/MDI/mdi_plugin.h
index c70a09975e..3299658dc8 100644
--- a/src/MDI/mdi_plugin.h
+++ b/src/MDI/mdi_plugin.h
@@ -25,7 +25,6 @@ class MDIPlugin : protected Pointers {
 
  private:
   char *lammps_command;
-  class Fix *fixptr;
 
   static int plugin_wrapper(void *, MDI_Comm, void *);
 };