Index: gcc/fortran/decl.c
===================================================================
*** gcc/fortran/decl.c	(revision 230783)
--- gcc/fortran/decl.c	(working copy)
*************** ok:
*** 4817,4830 ****
        goto cleanup;
      }
  
!   if (formal)
      {
        for (p = formal, q = head; p && q; p = p->next, q = q->next)
  	{
  	  if ((p->next != NULL && q->next == NULL)
  	      || (p->next == NULL && q->next != NULL))
! 	    gfc_error_now ("Mismatch in number of MODULE PROCEDURE "
! 		           "formal arguments at %C");
  	  else if ((p->sym == NULL && q->sym == NULL)
  		    || strcmp (p->sym->name, q->sym->name) == 0)
  	    continue;
--- 4817,4839 ----
        goto cleanup;
      }
  
!   if (progname->attr.module_procedure && progname->attr.host_assoc)
      {
+       bool arg_count_mismatch = false;
+ 
+       if (!formal && head)
+ 	arg_count_mismatch = true;
+ 
+       /* Abreviated module procedure declaration is not meant to have any
+ 	 formal arguments!  */
+       if (!sym->abr_modproc_decl && formal && !head)
+ 	arg_count_mismatch = true;
+ 
        for (p = formal, q = head; p && q; p = p->next, q = q->next)
  	{
  	  if ((p->next != NULL && q->next == NULL)
  	      || (p->next == NULL && q->next != NULL))
! 	    arg_count_mismatch = true;
  	  else if ((p->sym == NULL && q->sym == NULL)
  		    || strcmp (p->sym->name, q->sym->name) == 0)
  	    continue;
*************** ok:
*** 4833,4838 ****
--- 4842,4851 ----
  			   "argument names (%s/%s) at %C",
  			   p->sym->name, q->sym->name);
  	}
+ 
+       if (arg_count_mismatch)
+ 	gfc_error_now ("Mismatch in number of MODULE PROCEDURE "
+ 		       "formal arguments at %C");
      }
  
    return MATCH_YES;
Index: gcc/testsuite/gfortran.dg/submodule_13.f08
===================================================================
*** gcc/testsuite/gfortran.dg/submodule_13.f08	(revision 0)
--- gcc/testsuite/gfortran.dg/submodule_13.f08	(working copy)
***************
*** 0 ****
--- 1,32 ----
+ ! { dg-do compile }
+ !
+ ! Checks the fix for PR68534 in which checks for the number
+ ! failed if either the interface or the module procedure had
+ ! no dummies.
+ !
+ ! Reported on clf at:
+ ! https://groups.google.com/forum/#!topic/comp.lang.fortran/-ZgbM5qkFmc
+ !
+ module m
+   implicit none
+     interface
+       module subroutine foo()
+       end subroutine foo
+ 
+       module subroutine bar(i)
+         integer, intent(inout) :: i
+       end subroutine bar
+    end interface
+ end module m
+ 
+ submodule(m) sm
+ contains
+   module subroutine foo(i) ! { dg-error "Mismatch in number of MODULE PROCEDURE formal" }
+     integer, intent(inout) :: i
+     i = 42
+   end subroutine foo
+ 
+   module subroutine bar ! { dg-error "Mismatch in number of MODULE PROCEDURE formal" }
+     print *, "bar"
+   end subroutine bar
+ end submodule sm