diff --git a/boost/Makefile.am b/boost/Makefile.am
index 68c8f78625..b7c5a327f7 100644
--- a/boost/Makefile.am
+++ b/boost/Makefile.am
@@ -23,10 +23,6 @@ liblyxboost_la_SOURCES = \
 else
 
 liblyxboost_la_SOURCES = \
-	\
-	libs/iostreams/src/file_descriptor.cpp \
-	libs/iostreams/src/mapped_file.cpp \
-	libs/iostreams/src/zlib.cpp \
 	\
 	libs/filesystem/src/exception.cpp \
 	libs/filesystem/src/operations.cpp \
diff --git a/boost/lyxboost.cpp b/boost/lyxboost.cpp
index a41e1bd5ad..5501c290a9 100644
--- a/boost/lyxboost.cpp
+++ b/boost/lyxboost.cpp
@@ -1,7 +1,3 @@
-#include "libs/iostreams/src/file_descriptor.cpp"
-#include "libs/iostreams/src/mapped_file.cpp"
-#include "libs/iostreams/src/zlib.cpp"
-
 #include "libs/filesystem/src/exception.cpp"
 #include "libs/filesystem/src/operations.cpp"
 #include "libs/filesystem/src/path.cpp"
diff --git a/boost/pch.h b/boost/pch.h
index 44ce6928de..38644dd565 100644
--- a/boost/pch.h
+++ b/boost/pch.h
@@ -18,8 +18,6 @@
 #include <cerrno>
 #include <climits>
 #include <clocale>
-#include <cstdio>      // for remove, rename
-#include <cstring> // SGI MIPSpro compilers need this
 #include <cwchar>
 #include <iostream>
 #include <list>