diff --git a/src/maths/KLU/amd_internal.h b/src/maths/KLU/amd_internal.h
index 750aee82b..09452963e 100644
--- a/src/maths/KLU/amd_internal.h
+++ b/src/maths/KLU/amd_internal.h
@@ -162,7 +162,7 @@
 /* ------------------------------------------------------------------------- */
 
 /* define UF_long */
-#include "UFconfig.h"
+#include "ngspice/UFconfig.h"
 
 #if defined (DLONG) || defined (ZLONG)
 
@@ -219,7 +219,7 @@
 /* AMD routine definitions (user-callable) */
 /* ------------------------------------------------------------------------- */
 
-#include "amd.h"
+#include "ngspice/amd.h"
 
 /* ------------------------------------------------------------------------- */
 /* AMD routine definitions (not user-callable) */
diff --git a/src/maths/KLU/btf_maxtrans.c b/src/maths/KLU/btf_maxtrans.c
index e5df01e68..87034c3d4 100644
--- a/src/maths/KLU/btf_maxtrans.c
+++ b/src/maths/KLU/btf_maxtrans.c
@@ -45,7 +45,7 @@
  * with support from Sandia National Laboratories.  All Rights Reserved.
  */
 
-#include "btf.h"
+#include "ngspice/btf.h"
 #include "btf_internal.h"
 
 
diff --git a/src/maths/KLU/btf_order.c b/src/maths/KLU/btf_order.c
index 7198d0cdd..6e1826723 100644
--- a/src/maths/KLU/btf_order.c
+++ b/src/maths/KLU/btf_order.c
@@ -26,7 +26,7 @@
  * with support from Sandia National Laboratories.  All Rights Reserved.
  */
 
-#include "btf.h"
+#include "ngspice/btf.h"
 #include "btf_internal.h"
 
 /* This function only operates on square matrices (either structurally full-
diff --git a/src/maths/KLU/btf_strongcomp.c b/src/maths/KLU/btf_strongcomp.c
index aeb555ad8..3ecd0ad87 100644
--- a/src/maths/KLU/btf_strongcomp.c
+++ b/src/maths/KLU/btf_strongcomp.c
@@ -10,7 +10,7 @@
  * with support from Sandia National Laboratories.  All Rights Reserved.
  */
 
-#include "btf.h"
+#include "ngspice/btf.h"
 #include "btf_internal.h"
 
 #define UNVISITED (-2)      /* Flag [j] = UNVISITED if node j not visited yet */
diff --git a/src/maths/KLU/colamd.c b/src/maths/KLU/colamd.c
index f58e33c1e..182114b85 100644
--- a/src/maths/KLU/colamd.c
+++ b/src/maths/KLU/colamd.c
@@ -663,7 +663,7 @@
 /* === Include files ======================================================== */
 /* ========================================================================== */
 
-#include "colamd.h"
+#include "ngspice/colamd.h"
 #include <limits.h>
 #include <math.h>
 
@@ -685,7 +685,7 @@
 /* ========================================================================== */
 
 /* define UF_long */
-#include "UFconfig.h"
+#include "ngspice/UFconfig.h"
 
 #ifdef DLONG
 
diff --git a/src/maths/KLU/klu_internal.h b/src/maths/KLU/klu_internal.h
index 9ed269bbf..032aecca8 100644
--- a/src/maths/KLU/klu_internal.h
+++ b/src/maths/KLU/klu_internal.h
@@ -7,8 +7,8 @@
 #ifndef _KLU_INTERNAL_H
 #define _KLU_INTERNAL_H
 
-#include "klu.h"
-#include "btf.h"
+#include "ngspice/klu.h"
+#include "ngspice/btf.h"
 #include "klu_version.h"
 
 /* ========================================================================== */