diff --git a/src/eweight.c b/src/eweight.c
index 3aa09b82..aa4358b5 100644
--- a/src/eweight.c
+++ b/src/eweight.c
@@ -32,7 +32,7 @@ eweight_target_f(double Neff, void *params, double *ret_fx)
 
   p7_hmm_CopyParameters(p->hmm, p->h2);
   p7_hmm_Scale(p->h2, Neff / (double) p->h2->nseq);
-  p7_ParameterEstimation(p->h2, p->pri);
+  p7_ParameterEstimation_MatchOnly(p->h2, p->pri);
   *ret_fx = p7_MeanMatchRelativeEntropy(p->h2, p->bg) - p->etarget;
   return eslOK;
 }
@@ -107,7 +107,7 @@ eweight_target_exp_f(double exp, void *params, double *ret_fx)
 
   p7_hmm_CopyParameters(p->hmm, p->h2);
   p7_hmm_ScaleExponential(p->h2, exp);
-  p7_ParameterEstimation(p->h2, p->pri);
+  p7_ParameterEstimation_MatchOnly(p->h2, p->pri);
   *ret_fx = p7_MeanMatchRelativeEntropy(p->h2, p->bg) - p->etarget;
   return eslOK;
 }
diff --git a/src/hmmer.h b/src/hmmer.h
index 49fa3514..0b1bc4b0 100644
--- a/src/hmmer.h
+++ b/src/hmmer.h
@@ -1588,6 +1588,7 @@ extern P7_PRIOR  *p7_prior_CreateLaplace(const ESL_ALPHABET *abc);
 extern void       p7_prior_Destroy(P7_PRIOR *pri);
 
 extern int        p7_ParameterEstimation(P7_HMM *hmm, const P7_PRIOR *pri);
+extern int        p7_ParameterEstimation_MatchOnly(P7_HMM *hmm, const P7_PRIOR *pri);
 
 /* p7_profile.c */
 extern P7_PROFILE    *p7_profile_Create(int M, const ESL_ALPHABET *abc);
diff --git a/src/p7_prior.c b/src/p7_prior.c
index 6323e38a..0968da52 100644
--- a/src/p7_prior.c
+++ b/src/p7_prior.c
@@ -277,6 +277,30 @@ p7_prior_Destroy(P7_PRIOR *pri)
 
 
 
+/* Function:  p7_ParameterEstimation_MatchOnly()
+ * Purpose:   Like p7_ParameterEstimation(), but only the match emissions.
+ *            For callers (entropy weighting) that only read hmm->mat.
+ */
+int
+p7_ParameterEstimation_MatchOnly(P7_HMM *hmm, const P7_PRIOR *pri)
+{
+  int   k;
+  double c[p7_MAXABET];
+  double p[p7_MAXABET];
+
+  if (pri==NULL) return p7_hmm_Renormalize(hmm);
+
+  for (k = 1; k <= hmm->M; k++) {
+    esl_vec_F2D(hmm->mat[k], hmm->abc->K, c);
+    esl_mixdchlet_MPParameters(pri->em, c, p);
+    esl_vec_D2F(p, hmm->abc->K, hmm->mat[k]);
+  }
+  esl_vec_FSet(hmm->mat[0], hmm->abc->K, 0.);
+  hmm->mat[0][0] = 1.0;
+  return eslOK;
+}
+
+
 /* Function:  p7_ParameterEstimation()
  * Incept:    SRE, Sat Mar 24 10:15:37 2007 [Janelia]
  *