diff --git a/.gitattributes b/.gitattributes
index 63c04e580f5..7b050f83e4e 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -298,8 +298,8 @@ Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Real_roots.h -text
 Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/construct_binary.h -text
 Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/refine_zero_against.h -text
 Algebraic_kernel_d/include/CGAL/Filtered_algebraic_curve_kernel_2.h -text
-Algebraic_kernel_d/include/CGAL/Prefered_algebraic_curve_kernels_2.h -text
-Algebraic_kernel_d/include/CGAL/Prefered_algebraic_kernels_1.h -text
+Algebraic_kernel_d/include/CGAL/Preferred_algebraic_curve_kernels_2.h -text
+Algebraic_kernel_d/include/CGAL/Preferred_algebraic_kernels_1.h -text
 Algebraic_kernel_d/include/CGAL/Rotated_algebraic_curve_kernel_2.h -text
 Algebraic_kernel_d/package_info/Algebraic_kernel_d/maintainer -text
 Algebraic_kernel_d/test/Algebraic_curve_kernel_2/Algebraic_curve_kernel_2.cpp -text
diff --git a/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/arrangements_2.cpp b/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/arrangements_2.cpp
index 8e2e851d4f4..6345b6a40b5 100644
--- a/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/arrangements_2.cpp
+++ b/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/arrangements_2.cpp
@@ -43,7 +43,7 @@ CGAL::Timer overall_timer;
 #include <CGAL/Timer.h>
 
 #include <CGAL/Arithmetic_kernel.h>
-#include <CGAL/Prefered_algebraic_curve_kernels_2.h>
+#include <CGAL/Preferred_algebraic_curve_kernels_2.h>
 
 
 #if CGAL_ACK_USE_FILTERED_CKvA_2
diff --git a/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_analyser_2.cpp b/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_analyser_2.cpp
index e4d0753c91b..afd528fc1e5 100644
--- a/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_analyser_2.cpp
+++ b/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_analyser_2.cpp
@@ -55,7 +55,7 @@ CGAL::Timer overall_timer;
 #include <CGAL/Arithmetic_kernel.h>
 #include <CGAL/Algebraic_kernel_d/Algebraic_real_quadratic_refinement_rep_bfi.h>
 #include <CGAL/Algebraic_kernel_d/Bitstream_descartes.h>
-#include <CGAL/Prefered_algebraic_curve_kernels_2.h>
+#include <CGAL/Preferred_algebraic_curve_kernels_2.h>
 
 void print_help(char* execname) {
   std::cout << "Usage: " << execname 
diff --git a/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_pair_analyser_2.cpp b/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_pair_analyser_2.cpp
index 83b7c923ef9..e9dedcee0e5 100644
--- a/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_pair_analyser_2.cpp
+++ b/Algebraic_kernel_d/demo/Algebraic_curve_kernel_2/curve_pair_analyser_2.cpp
@@ -37,7 +37,7 @@ CGAL::Timer first_curve_timer, second_curve_timer,
   pair_timer;
 
 #include <CGAL/Arithmetic_kernel.h>
-#include <CGAL/Prefered_algebraic_curve_kernels_2.h>
+#include <CGAL/Preferred_algebraic_curve_kernels_2.h>
 
 void print_help(char* execname) {
   std::cout << "Usage: " << execname 
diff --git a/Algebraic_kernel_d/include/CGAL/Prefered_algebraic_curve_kernels_2.h b/Algebraic_kernel_d/include/CGAL/Preferred_algebraic_curve_kernels_2.h
similarity index 99%
rename from Algebraic_kernel_d/include/CGAL/Prefered_algebraic_curve_kernels_2.h
rename to Algebraic_kernel_d/include/CGAL/Preferred_algebraic_curve_kernels_2.h
index 29eb9f8cbe7..1e6f5d5ed53 100644
--- a/Algebraic_kernel_d/include/CGAL/Prefered_algebraic_curve_kernels_2.h
+++ b/Algebraic_kernel_d/include/CGAL/Preferred_algebraic_curve_kernels_2.h
@@ -24,7 +24,7 @@
 #include <CGAL/Arithmetic_kernel.h>
 #include <CGAL/Algebraic_curve_kernel_2.h>
 #include <CGAL/Filtered_algebraic_curve_kernel_2.h>
-#include <CGAL/Prefered_algebraic_kernels_1.h>
+#include <CGAL/Preferred_algebraic_kernels_1.h>
 
 CGAL_BEGIN_NAMESPACE
 
diff --git a/Algebraic_kernel_d/include/CGAL/Prefered_algebraic_kernels_1.h b/Algebraic_kernel_d/include/CGAL/Preferred_algebraic_kernels_1.h
similarity index 100%
rename from Algebraic_kernel_d/include/CGAL/Prefered_algebraic_kernels_1.h
rename to Algebraic_kernel_d/include/CGAL/Preferred_algebraic_kernels_1.h