diff -up gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/CMakeLists.txt.lmfit gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/CMakeLists.txt
--- gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/CMakeLists.txt.lmfit	2016-05-10 16:55:17.000000000 +0200
+++ gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/CMakeLists.txt	2016-05-12 12:33:06.416806977 +0200
@@ -204,6 +204,7 @@ target_link_libraries(libgromacs
                       ${GMX_EXTRA_LIBRARIES}
                       ${TNG_IO_LIBRARIES}
                       ${FFT_LIBRARIES} ${LINEAR_ALGEBRA_LIBRARIES}
+                      ${LMFIT_LIBRARIES}
                       ${XML_LIBRARIES}
                       ${THREAD_LIB} ${GMX_SHARED_LINKER_FLAGS} ${OPENCL_LIBRARIES}
                       ${GMX_STDLIB_LIBRARIES})
diff -up gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/CMakeLists.txt.lmfit gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/CMakeLists.txt
--- gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/CMakeLists.txt.lmfit	2016-05-10 16:55:17.000000000 +0200
+++ gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/CMakeLists.txt	2016-05-12 12:33:06.416806977 +0200
@@ -33,9 +33,9 @@
 # the research papers on the package. Check out http://www.gromacs.org.
 
 file(GLOB GMXCORRFUNC_SOURCES *.cpp)
-file(GLOB LMFIT_SOURCES ${CMAKE_SOURCE_DIR}/src/external/lmfit/*.cpp)
+find_library(LMFIT_LIBRARIES lmfit)
 
-set(LIBGROMACS_SOURCES ${LIBGROMACS_SOURCES} ${GMXCORRFUNC_SOURCES}  ${LMFIT_SOURCES} PARENT_SCOPE)
+set(LIBGROMACS_SOURCES ${LIBGROMACS_SOURCES} ${GMXCORRFUNC_SOURCES} PARENT_SCOPE)
 if (BUILD_TESTING)
     add_subdirectory(tests)
 endif()
diff -up gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/expfit.cpp.lmfit gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/expfit.cpp
--- gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/expfit.cpp.lmfit	2016-05-10 16:55:17.000000000 +0200
+++ gromacs-d44d7d6bebdb7fa52090b744854d49f34099e044/src/gromacs/correlationfunctions/expfit.cpp	2016-05-12 12:49:08.266651639 +0200
@@ -52,7 +52,7 @@
 
 #include <algorithm>
 
-#include "external/lmfit/gmx_lmcurve.h"
+#include <lmcurve_tyd.h>
 
 #include "gromacs/correlationfunctions/integrate.h"
 #include "gromacs/fileio/xvgr.h"
@@ -448,7 +448,7 @@ static gmx_bool lmfit_exp(int          n
     /* Using default control structure for double precision fitting that
      * comes with the lmfit package (i.e. from the include file).
      */
-    control            = gmx_lm_control_double;
+    control            = lm_control_double;
     control.verbosity  = (bVerbose ? 1 : 0);
     control.n_maxpri   = 0;
     control.m_maxpri   = 0;
@@ -483,14 +483,14 @@ static gmx_bool lmfit_exp(int          n
     do
     {
         ochisq = chisq;
-        gmx_lmcurve(nparam, parm, nfit, x, y, dy,
+        lmcurve_tyd(nparam, parm, nfit, x, y, dy,
                     lmcurves[eFitFn], &control, status);
         chisq = gmx::square(status->fnorm);
         if (bVerbose)
         {
             printf("status: fnorm = %g, nfev = %d, userbreak = %d\noutcome = %s\n",
                    status->fnorm, status->nfev, status->userbreak,
-                   gmx_lm_infmsg[status->outcome]);
+                   lm_infmsg[status->outcome]);
         }
         if (bVerbose)
         {