diff -rupN gmsh-4.0.7-source/contrib/HighOrderMeshOptimizer/OptHOM.cpp gmsh-4.0.7-source-new/contrib/HighOrderMeshOptimizer/OptHOM.cpp
--- gmsh-4.0.7-source/contrib/HighOrderMeshOptimizer/OptHOM.cpp	2018-10-21 12:15:16.000000000 +0200
+++ gmsh-4.0.7-source-new/contrib/HighOrderMeshOptimizer/OptHOM.cpp	2018-12-10 16:42:02.619728663 +0100
@@ -41,11 +41,11 @@ static int NEVAL = 0;
 
 #if defined(HAVE_BFGS)
 
-#include "ap.h"
-#include "alglibinternal.h"
-#include "alglibmisc.h"
-#include "linalg.h"
-#include "optimization.h"
+#include <alglib/ap.h>
+#include <alglib/alglibinternal.h>
+#include <alglib/alglibmisc.h>
+#include <alglib/linalg.h>
+#include <alglib/optimization.h>
 
 static inline double compute_f(double v, double barrier)
 {
diff -rupN gmsh-4.0.7-source/contrib/HighOrderMeshOptimizer/OptHOM.h gmsh-4.0.7-source-new/contrib/HighOrderMeshOptimizer/OptHOM.h
--- gmsh-4.0.7-source/contrib/HighOrderMeshOptimizer/OptHOM.h	2018-10-21 12:15:16.000000000 +0200
+++ gmsh-4.0.7-source-new/contrib/HighOrderMeshOptimizer/OptHOM.h	2018-12-10 16:42:02.619728663 +0100
@@ -35,7 +35,7 @@
 
 #if defined(HAVE_BFGS)
 
-#include "ap.h"
+#include <alglib/ap.h>
 
 class OptHOM
 {
diff -rupN gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOpt.cpp gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOpt.cpp
--- gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOpt.cpp	2018-10-21 12:15:16.000000000 +0200
+++ gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOpt.cpp	2018-12-10 16:42:02.619728663 +0100
@@ -35,11 +35,11 @@
 
 #if defined(HAVE_BFGS)
 
-#include "ap.h"
-#include "alglibinternal.h"
-#include "alglibmisc.h"
-#include "linalg.h"
-#include "optimization.h"
+#include <alglib/ap.h>
+#include <alglib/alglibinternal.h>
+#include <alglib/alglibmisc.h>
+#include <alglib/linalg.h>
+#include <alglib/optimization.h>
 
 namespace {
 
diff -rupN gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOpt.h gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOpt.h
--- gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOpt.h	2018-10-21 12:15:16.000000000 +0200
+++ gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOpt.h	2018-12-10 16:42:02.619728663 +0100
@@ -39,7 +39,7 @@
 
 #if defined(HAVE_BFGS)
 
-#include "ap.h"
+#include <alglib/ap.h>
 
 class MeshOptParameters;
 
diff -rupN gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOptObjContrib.h gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOptObjContrib.h
--- gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOptObjContrib.h	2017-10-03 22:01:51.000000000 +0200
+++ gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOptObjContrib.h	2018-12-10 16:42:02.620728662 +0100
@@ -4,7 +4,7 @@
 #define _MESHOPTOBJCONTRIB_H_
 
 #include <string>
-#include "ap.h"
+#include <alglib/ap.h>
 #include "MeshOptCommon.h"
 
 
diff -rupN gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOptObjectiveFunction.h gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOptObjectiveFunction.h
--- gmsh-4.0.7-source/contrib/MeshOptimizer/MeshOptObjectiveFunction.h	2017-10-03 22:01:51.000000000 +0200
+++ gmsh-4.0.7-source-new/contrib/MeshOptimizer/MeshOptObjectiveFunction.h	2018-12-10 16:42:02.620728662 +0100
@@ -5,7 +5,7 @@
 
 #include <string>
 #include <vector>
-#include "ap.h"
+#include <alglib/ap.h>
 
 class ObjContrib;
 class Patch;
diff -rupN gmsh-4.0.7-source/Geo/GFace.cpp gmsh-4.0.7-source-new/Geo/GFace.cpp
--- gmsh-4.0.7-source/Geo/GFace.cpp	2018-12-09 14:02:39.000000000 +0100
+++ gmsh-4.0.7-source-new/Geo/GFace.cpp	2018-12-10 16:42:02.620728662 +0100
@@ -27,8 +27,8 @@
 #endif
 
 #if defined(HAVE_BFGS)
-#include "stdafx.h"
-#include "optimization.h"
+#include <alglib/stdafx.h>
+#include <alglib/optimization.h>
 #endif
 
 // TODO C++11 remove macro