diff --git a/OOXML/DocxFormat/Media/ActiveX.h b/OOXML/DocxFormat/Media/ActiveX.h
index e600841ade..bf0cd3496a 100644
--- a/OOXML/DocxFormat/Media/ActiveX.h
+++ b/OOXML/DocxFormat/Media/ActiveX.h
@@ -37,6 +37,7 @@
 #include "../../Common/SimpleTypes_Shared.h"
 #include "../IFileContainer.h"
 #include "../Document.h"
+#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
 
 #include <boost/smart_ptr/shared_array.hpp>
 
diff --git a/OOXML/XlsxFormat/SharedStrings/PhoneticPr.cpp b/OOXML/XlsxFormat/SharedStrings/PhoneticPr.cpp
index 4ae50e5a5f..9c5e43aabe 100644
--- a/OOXML/XlsxFormat/SharedStrings/PhoneticPr.cpp
+++ b/OOXML/XlsxFormat/SharedStrings/PhoneticPr.cpp
@@ -34,6 +34,7 @@
 
 #include "../../Common/SimpleTypes_Shared.h"
 #include "../../XlsbFormat/Biff12_structures/PhRun.h"
+#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
 
 namespace OOX
 {
diff --git a/OOXML/XlsxFormat/SharedStrings/PhoneticPr.h b/OOXML/XlsxFormat/SharedStrings/PhoneticPr.h
index f02e7f180c..1f5c68f63a 100644
--- a/OOXML/XlsxFormat/SharedStrings/PhoneticPr.h
+++ b/OOXML/XlsxFormat/SharedStrings/PhoneticPr.h
@@ -32,7 +32,11 @@
 #pragma once
 
 #include "Text.h"
-#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
+
+namespace XLS
+{
+	class BiffStructure;
+}
 
 namespace SimpleTypes
 {
diff --git a/OOXML/XlsxFormat/Slicer/SlicerCache.cpp b/OOXML/XlsxFormat/Slicer/SlicerCache.cpp
index 11a56de06e..706de69788 100644
--- a/OOXML/XlsxFormat/Slicer/SlicerCache.cpp
+++ b/OOXML/XlsxFormat/Slicer/SlicerCache.cpp
@@ -56,6 +56,8 @@
 #include "../../Common/SimpleTypes_Spreadsheet.h"
 #include "../../DocxFormat/Drawing/DrawingExt.h"
 
+#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
+
 namespace OOX
 {
 namespace Spreadsheet
diff --git a/OOXML/XlsxFormat/Slicer/SlicerCache.h b/OOXML/XlsxFormat/Slicer/SlicerCache.h
index af07ae91de..6ddd78e12f 100644
--- a/OOXML/XlsxFormat/Slicer/SlicerCache.h
+++ b/OOXML/XlsxFormat/Slicer/SlicerCache.h
@@ -37,7 +37,10 @@
 #include "../FileTypes_Spreadsheet.h"
 #include "../../DocxFormat/IFileContainer.h"
 
-#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
+namespace XLS
+{
+	class BiffStructure;
+}
 
 namespace SimpleTypes
 {
diff --git a/OOXML/XlsxFormat/Slicer/SlicerCacheExt.cpp b/OOXML/XlsxFormat/Slicer/SlicerCacheExt.cpp
index 1abd4bc2f0..94610a61dc 100644
--- a/OOXML/XlsxFormat/Slicer/SlicerCacheExt.cpp
+++ b/OOXML/XlsxFormat/Slicer/SlicerCacheExt.cpp
@@ -54,6 +54,8 @@
 #include "../../Common/SimpleTypes_Spreadsheet.h"
 #include "../../DocxFormat/Drawing/DrawingExt.h"
 
+#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
+
 namespace OOX
 {
 namespace Spreadsheet
diff --git a/OOXML/XlsxFormat/Slicer/SlicerCacheExt.h b/OOXML/XlsxFormat/Slicer/SlicerCacheExt.h
index b5b61debe5..61744a9407 100644
--- a/OOXML/XlsxFormat/Slicer/SlicerCacheExt.h
+++ b/OOXML/XlsxFormat/Slicer/SlicerCacheExt.h
@@ -34,8 +34,10 @@
 #include "../WritingElement.h"
 #include "../../Base/Nullable.h"
 
-#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
-
+namespace XLS
+{
+	class BiffStructure;
+}
 
 namespace SimpleTypes
 {
diff --git a/OOXML/XlsxFormat/Styles/Borders.cpp b/OOXML/XlsxFormat/Styles/Borders.cpp
index 765b77f95c..e49b7505de 100644
--- a/OOXML/XlsxFormat/Styles/Borders.cpp
+++ b/OOXML/XlsxFormat/Styles/Borders.cpp
@@ -36,6 +36,7 @@
 #include "../../Common/SimpleTypes_Spreadsheet.h"
 
 #include "../../XlsbFormat/Biff12_records/Border.h"
+#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
 
 namespace OOX
 {
diff --git a/OOXML/XlsxFormat/Styles/Borders.h b/OOXML/XlsxFormat/Styles/Borders.h
index f2d38f2df8..7d45af52f0 100644
--- a/OOXML/XlsxFormat/Styles/Borders.h
+++ b/OOXML/XlsxFormat/Styles/Borders.h
@@ -32,7 +32,11 @@
 #pragma once
 
 #include "rPr.h"
-#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
+
+namespace XLS
+{
+	class BiffStructure;
+}
 
 namespace SimpleTypes
 {
diff --git a/OOXML/XlsxFormat/Styles/Fills.cpp b/OOXML/XlsxFormat/Styles/Fills.cpp
index 8164832770..4dcf7249c9 100644
--- a/OOXML/XlsxFormat/Styles/Fills.cpp
+++ b/OOXML/XlsxFormat/Styles/Fills.cpp
@@ -36,6 +36,7 @@
 #include "../../Common/SimpleTypes_Spreadsheet.h"
 
 #include "../../XlsbFormat/Biff12_records/Fill.h"
+#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
 
 namespace OOX
 {
diff --git a/OOXML/XlsxFormat/Styles/Fills.h b/OOXML/XlsxFormat/Styles/Fills.h
index 024c1dead3..53021d8dc0 100644
--- a/OOXML/XlsxFormat/Styles/Fills.h
+++ b/OOXML/XlsxFormat/Styles/Fills.h
@@ -32,7 +32,11 @@
 #pragma once
 
 #include "rPr.h"
-#include "../../../MsBinaryFile/XlsFile/Format/Logic/Biff_structures/BiffStructure.h"
+
+namespace XLS
+{
+	class BiffStructure;
+}
 
 namespace SimpleTypes
 {