diff --git a/include/cantera/numerics/ctlapack.h b/include/cantera/numerics/ctlapack.h
index 0e3e6cc1e..8a3d5f7cd 100644
--- a/include/cantera/numerics/ctlapack.h
+++ b/include/cantera/numerics/ctlapack.h
@@ -19,6 +19,7 @@
 #define _DGETRF_  dgetrf
 #define _DGETRS_  dgetrs
 #define _DGETRI_  dgetri
+#define _DGELSS_  dgelss
 #define _DGBCON_  dgbcon
 #define _DGBSV_   dgbsv
 #define _DGBTRF_  dgbtrf
@@ -39,6 +40,7 @@
 #define _DGETRF_  dgetrf_
 #define _DGETRS_  dgetrs_
 #define _DGETRI_  dgetri_
+#define _DGELSS_  dgelss_
 #define _DGBCON_  dgbcon_
 #define _DGBSV_   dgbsv_
 #define _DGBTRF_  dgbtrf_
@@ -107,6 +109,11 @@ extern "C" {
     int _DGETRI_(const integer* n, doublereal* a, const integer* lda,
                  integer* ipiv, doublereal* work, integer* lwork, integer* info);
 
+    int _DGELSS_(const integer* m, const integer* n, const integer* nrhs,
+                 doublereal* a, const integer* lda, doublereal* b,
+                 const integer* ldb, doublereal* s, const doublereal* rcond,
+                 integer* rank, doublereal* work, integer* lwork, integer* info);
+
     int _DGBSV_(integer* n, integer* kl, integer* ku, integer* nrhs,
                 doublereal* a, integer* lda, integer* ipiv, doublereal* b,
                 integer* ldb, integer* info);
@@ -251,6 +258,27 @@ inline void ct_dgbsv(int n, int kl, int ku, int nrhs,
     info = f_info;
 }
 
+inline void ct_dgelss(size_t m, size_t n, size_t nrhs, doublereal* a,
+                      size_t lda, doublereal* b, size_t ldb, doublereal* s,
+                      doublereal rcond, size_t& rank, doublereal* work,
+                      int& lwork, int& info)
+{
+    integer f_m = static_cast<integer>(m);
+    integer f_n = static_cast<integer>(n);
+    integer f_nrhs = static_cast<integer>(nrhs);
+    integer f_lda = static_cast<integer>(lda);
+    integer f_ldb = static_cast<integer>(ldb);
+    integer f_lwork = static_cast<integer>(lwork);
+    integer f_rank, f_info;
+
+    _DGELSS_(&f_m, &f_n, &f_nrhs, a, &f_lda, b, &f_ldb, s, &rcond, &f_rank,
+            work, &f_lwork, &f_info);
+
+    info = static_cast<int>(f_info);
+    rank = static_cast<size_t>(f_rank);
+    lwork = static_cast<int>(f_lwork);
+}
+
 inline void ct_dgbtrf(size_t m, size_t n, size_t kl, size_t ku,
                       doublereal* a, size_t lda, integer* ipiv, int& info)
 {