diff --git a/src/FDM/YASim/yasim-test.cpp b/src/FDM/YASim/yasim-test.cpp
index 883326ade..9c6a4f352 100644
--- a/src/FDM/YASim/yasim-test.cpp
+++ b/src/FDM/YASim/yasim-test.cpp
@@ -10,7 +10,7 @@
 #include "Atmosphere.hpp"
 #include "Airplane.hpp"
 
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 using namespace yasim;
 
diff --git a/src/GUI/layout-props.cxx b/src/GUI/layout-props.cxx
index d32eac552..09764096c 100644
--- a/src/GUI/layout-props.cxx
+++ b/src/GUI/layout-props.cxx
@@ -4,7 +4,7 @@
 
 #include <plib/pu.h>
 #include <simgear/props/props.hxx>
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 #include "layout.hxx"
 
diff --git a/src/GUI/layout.cxx b/src/GUI/layout.cxx
index aac89f550..f9581b3d5 100644
--- a/src/GUI/layout.cxx
+++ b/src/GUI/layout.cxx
@@ -5,7 +5,7 @@
 
 #include "layout.hxx"
 
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 // This file contains the actual layout engine.  It has no dependence
 // on outside libraries; see layout-props.cxx for the glue code.
diff --git a/src/Main/bootstrap.cxx b/src/Main/bootstrap.cxx
index c42a68502..9f2fcbb6d 100644
--- a/src/Main/bootstrap.cxx
+++ b/src/Main/bootstrap.cxx
@@ -42,7 +42,7 @@
 #include <simgear/compiler.h>
 #include <simgear/structure/exception.hxx>
 #include <simgear/debug/logstream.hxx>
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 #include <cstring>
 #include <iostream>
diff --git a/src/Main/fg_props.hxx b/src/Main/fg_props.hxx
index 6fa9001f8..8516c93c9 100644
--- a/src/Main/fg_props.hxx
+++ b/src/Main/fg_props.hxx
@@ -9,7 +9,7 @@
 #include <iosfwd>
 
 #include <simgear/structure/subsystem_mgr.hxx>
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 #include <Main/globals.hxx>
 
diff --git a/src/Model/model_panel.cxx b/src/Model/model_panel.cxx
index 8a581d2f4..eef538cb0 100644
--- a/src/Model/model_panel.cxx
+++ b/src/Model/model_panel.cxx
@@ -14,7 +14,7 @@
 #include <simgear/props/props.hxx>
 #include <simgear/scene/model/modellib.hxx>
 #include <simgear/scene/util/SGNodeMasks.hxx>
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 #include "panelnode.hxx"
 #include "model_panel.hxx"
diff --git a/src/Scenery/SceneryPager.cxx b/src/Scenery/SceneryPager.cxx
index 577677f9e..6f79a56ee 100644
--- a/src/Scenery/SceneryPager.cxx
+++ b/src/Scenery/SceneryPager.cxx
@@ -21,7 +21,7 @@
 #endif
 
 #include <simgear/scene/model/SGPagedLOD.hxx>
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 #include "SceneryPager.hxx"
 #include <algorithm>
 #include <functional>
diff --git a/utils/GPSsmooth/UGear_telnet.cxx b/utils/GPSsmooth/UGear_telnet.cxx
index 42a40edf4..602a6a9d8 100644
--- a/utils/GPSsmooth/UGear_telnet.cxx
+++ b/utils/GPSsmooth/UGear_telnet.cxx
@@ -25,7 +25,7 @@
 
 #include <simgear/structure/commands.hxx>
 #include <simgear/misc/strutils.hxx>
-#include <simgear/Math/SGMath.hxx>
+#include <simgear/math/SGMath.hxx>
 
 #include <sstream>