diff --git a/DESCRIPTION b/DESCRIPTION
index f95fb21c..a1a69ffd 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Package: pomp
 Type: Package
 Title: Statistical Inference for Partially Observed Markov Processes
-Version: 5.4.1.0
-Date: 2023-08-08
+Version: 5.4.2.0
+Date: 2023-10-08
 Authors@R: c(person(given=c("Aaron","A."),family="King",role=c("aut","cre"),email="kingaa@umich.edu",comment=c(ORCID="0000-0001-6159-3207")),
 	  person(given=c("Edward","L."),family="Ionides",role="aut",comment=c(ORCID="0000-0002-4190-0174"))	,
 	  person(given="Carles",family="Bretó",role="aut",comment=c(ORCID="0000-0003-4695-4902")),
diff --git a/R/objfun.R b/R/objfun.R
index 88098378..ecc459f4 100644
--- a/R/objfun.R
+++ b/R/objfun.R
@@ -66,10 +66,10 @@ setMethod(
   }
 )
 
-setAs(
-  from="objfun",
-  to="pomp",
-  def = function (from) {
+setIs(
+  class1="objfun",
+  class2="pomp",
+  coerce = function (from) {
     as(from@env$object,"pomp")
   }
 )
diff --git a/inst/NEWS b/inst/NEWS
index 0a190c06..a8979ea7 100644
--- a/inst/NEWS
+++ b/inst/NEWS
@@ -1,5 +1,10 @@
 _N_e_w_s _f_o_r _p_a_c_k_a_g_e '_p_o_m_p'
 
+_C_h_a_n_g_e_s _i_n '_p_o_m_p' _v_e_r_s_i_o_n _5._4._2:
+
+        • State objective functions (class ‘objfun’) now behave as if
+          they are ‘pomp’ objects.
+
 _C_h_a_n_g_e_s _i_n '_p_o_m_p' _v_e_r_s_i_o_n _5._4._1:
 
         • C-level functions ‘set_pomp_userdata’ and
diff --git a/inst/NEWS.Rd b/inst/NEWS.Rd
index b9c301b8..9331cfd9 100644
--- a/inst/NEWS.Rd
+++ b/inst/NEWS.Rd
@@ -1,5 +1,10 @@
 \name{NEWS}
 \title{News for package `pomp'}
+\section{Changes in \pkg{pomp} version 5.4.2}{
+  \itemize{
+    \item State objective functions (class \sQuote{objfun}) now behave as if they are \sQuote{pomp} objects.
+  }
+}
 \section{Changes in \pkg{pomp} version 5.4.1}{
   \itemize{
     \item C-level functions \code{set_pomp_userdata} and \code{unset_pomp_userdata} are no longer exported.