diff --git a/unsupported/Eigen/src/NonLinear/lmder.h b/unsupported/Eigen/src/NonLinear/lmder.h
index 1d02c3684..dd43d8d7b 100644
--- a/unsupported/Eigen/src/NonLinear/lmder.h
+++ b/unsupported/Eigen/src/NonLinear/lmder.h
@@ -215,13 +215,8 @@ L200:
     /*           determine the levenberg-marquardt parameter. */
 
     ipvt.cwise()+=1; // lmpar() expects the fortran convention (as qrfac provides)
-#if 1
     ei_lmpar<Scalar>(n, fjac.data(), ldfjac, ipvt.data(), diag.data(), qtf.data(), delta,
-            &par, wa1.data(), wa2.data(), wa3.data(), wa4.data());
-#else
-    lmpar(n, fjac.data(), ldfjac, ipvt.data(), diag.data(), qtf.data(), delta,
-            &par, wa1.data(), wa2.data(), wa3.data(), wa4.data());
-#endif
+            par, wa1.data(), wa2.data(), wa3.data(), wa4.data());
     ipvt.cwise()-=1;
 
     /*           store the direction p and x + p. calculate the norm of p. */
diff --git a/unsupported/Eigen/src/NonLinear/lmdif.h b/unsupported/Eigen/src/NonLinear/lmdif.h
index 19af2005c..7e89de16e 100644
--- a/unsupported/Eigen/src/NonLinear/lmdif.h
+++ b/unsupported/Eigen/src/NonLinear/lmdif.h
@@ -219,7 +219,7 @@ L200:
 
     ipvt.cwise()+=1; // lmpar() expects the fortran convention (as qrfac provides)
     ei_lmpar<Scalar>(n, fjac.data(), ldfjac, ipvt.data(), diag.data(), qtf.data(), delta,
-            &par, wa1.data(), wa2.data(), wa3.data(), wa4.data());
+            par, wa1.data(), wa2.data(), wa3.data(), wa4.data());
     ipvt.cwise()-=1;
 
     /*           store the direction p and x + p. calculate the norm of p. */
diff --git a/unsupported/Eigen/src/NonLinear/lmpar.h b/unsupported/Eigen/src/NonLinear/lmpar.h
index 1c21fd7d3..32af22c49 100644
--- a/unsupported/Eigen/src/NonLinear/lmpar.h
+++ b/unsupported/Eigen/src/NonLinear/lmpar.h
@@ -2,7 +2,7 @@
 template <typename Scalar>
 void ei_lmpar(int n, Scalar *r__, int ldr, 
 	const int *ipvt, const Scalar *diag, const Scalar *qtb, Scalar delta, 
-	Scalar *par, Scalar *x, Scalar *sdiag, Scalar *wa1, 
+	Scalar &par, Scalar *x, Scalar *sdiag, Scalar *wa1, 
 	Scalar *wa2)
 {
     /* System generated locals */
@@ -142,10 +142,10 @@ L120:
 /*     if the input par lies outside of the interval (parl,paru), */
 /*     set par to the closer endpoint. */
 
-    *par = std::max(*par,parl);
-    *par = std::min(*par,paru);
-    if (*par == 0.) {
-	*par = gnorm / dxnorm;
+    par = std::max(par,parl);
+    par = std::min(par,paru);
+    if (par == 0.) {
+	par = gnorm / dxnorm;
     }
 
 /*     beginning of an iteration. */
@@ -155,12 +155,12 @@ L150:
 
 /*        evaluate the function at the current value of par. */
 
-    if (*par == 0.) {
+    if (par == 0.) {
 /* Computing MAX */
 	d__1 = dwarf, d__2 = Scalar(.001) * paru;
-	*par = std::max(d__1,d__2);
+	par = std::max(d__1,d__2);
     }
-    temp = ei_sqrt(*par);
+    temp = ei_sqrt(par);
     for (j = 1; j <= n; ++j) {
 	wa1[j] = temp * diag[j];
 /* L160: */
@@ -211,17 +211,17 @@ L200:
 /*        depending on the sign of the function, update parl or paru. */
 
     if (fp > 0.) {
-	parl = std::max(parl,*par);
+	parl = std::max(parl,par);
     }
     if (fp < 0.) {
-	paru = std::min(paru,*par);
+	paru = std::min(paru,par);
     }
 
 /*        compute an improved estimate for par. */
 
 /* Computing MAX */
-    d__1 = parl, d__2 = *par + parc;
-    *par = std::max(d__1,d__2);
+    d__1 = parl, d__2 = par + parc;
+    par = std::max(d__1,d__2);
 
 /*        end of an iteration. */
 
@@ -231,7 +231,7 @@ L220:
 /*     termination. */
 
     if (iter == 0) {
-	*par = 0.;
+	par = 0.;
     }
     return;
 
diff --git a/unsupported/Eigen/src/NonLinear/lmstr.h b/unsupported/Eigen/src/NonLinear/lmstr.h
index d05dc1ece..a96eaccb1 100644
--- a/unsupported/Eigen/src/NonLinear/lmstr.h
+++ b/unsupported/Eigen/src/NonLinear/lmstr.h
@@ -242,7 +242,7 @@ L240:
     /*           determine the levenberg-marquardt parameter. */
 
     ipvt.cwise()+=1; // lmpar() expects the fortran convention (as qrfac provides)
-    ei_lmpar<Scalar>(n, fjac.data(), ldfjac, ipvt.data(), diag.data(), qtf.data(), delta, &par,
+    ei_lmpar<Scalar>(n, fjac.data(), ldfjac, ipvt.data(), diag.data(), qtf.data(), delta, par,
             wa1.data(), wa2.data(), wa3.data(), wa4.data());
     ipvt.cwise()-=1;