diff --git a/codemaker/IwyuFilter_codemaker.yaml b/codemaker/IwyuFilter_codemaker.yaml
new file mode 100644
index 000000000000..32f5eaf602e3
--- /dev/null
+++ b/codemaker/IwyuFilter_codemaker.yaml
@@ -0,0 +1,2 @@
+---
+assumeFilename: codemaker/source/cppumaker/cppumaker.cxx
diff --git a/codemaker/source/cppumaker/cppumaker.cxx b/codemaker/source/cppumaker/cppumaker.cxx
index 3fe5c8855712..bd4c9feac045 100644
--- a/codemaker/source/cppumaker/cppumaker.cxx
+++ b/codemaker/source/cppumaker/cppumaker.cxx
@@ -22,7 +22,6 @@
 #include <cstdlib>
 #include <cstring>
 #include <iostream>
-#include <vector>
 
 #include <codemaker/generatedtypeset.hxx>
 #include <codemaker/typemanager.hxx>
diff --git a/codemaker/source/cppumaker/cpputype.cxx b/codemaker/source/cppumaker/cpputype.cxx
index 24846d054347..afe3c0b14de4 100644
--- a/codemaker/source/cppumaker/cpputype.cxx
+++ b/codemaker/source/cppumaker/cpputype.cxx
@@ -18,7 +18,6 @@
  */
 
 #include <sal/config.h>
-#include <sal/log.hxx>
 
 #include <algorithm>
 #include <cassert>
@@ -29,13 +28,10 @@
 #include <memory>
 #include <utility>
 #include <vector>
-#include <iostream>
 
-#include <rtl/alloc.h>
 #include <rtl/ref.hxx>
 #include <rtl/ustrbuf.hxx>
 #include <rtl/ustring.hxx>
-#include <rtl/strbuf.hxx>
 #include <unoidl/unoidl.hxx>
 
 #include <codemaker/commoncpp.hxx>
diff --git a/codemaker/source/cppumaker/cpputype.hxx b/codemaker/source/cppumaker/cpputype.hxx
index c41cfa287646..7937ef59576c 100644
--- a/codemaker/source/cppumaker/cpputype.hxx
+++ b/codemaker/source/cppumaker/cpputype.hxx
@@ -22,9 +22,9 @@
 #include <sal/config.h>
 
 #include <rtl/ref.hxx>
+#include <rtl/ustring.hxx>
 
 namespace codemaker { class GeneratedTypeSet; }
-namespace rtl { class OUString; }
 class CppuOptions;
 class TypeManager;
 
diff --git a/codemaker/source/cppumaker/dependencies.hxx b/codemaker/source/cppumaker/dependencies.hxx
index 0071397aa0ef..27a05ff4e524 100644
--- a/codemaker/source/cppumaker/dependencies.hxx
+++ b/codemaker/source/cppumaker/dependencies.hxx
@@ -25,8 +25,8 @@
 #include <string_view>
 
 #include <rtl/ref.hxx>
+#include <rtl/ustring.hxx>
 
-namespace rtl { class OUString; }
 class TypeManager;
 
 /// @HTML
diff --git a/codemaker/source/cppumaker/dumputils.cxx b/codemaker/source/cppumaker/dumputils.cxx
index 37e3ce629862..14b2e5ef429a 100644
--- a/codemaker/source/cppumaker/dumputils.cxx
+++ b/codemaker/source/cppumaker/dumputils.cxx
@@ -22,7 +22,6 @@
 
 #include <codemaker/global.hxx>
 
-#include <rtl/ustring.hxx>
 #include <sal/types.h>
 #include <o3tl/string_view.hxx>
 
diff --git a/codemaker/source/javamaker/classfile.cxx b/codemaker/source/javamaker/classfile.cxx
index fd32497508c6..09bdd090554b 100644
--- a/codemaker/source/javamaker/classfile.cxx
+++ b/codemaker/source/javamaker/classfile.cxx
@@ -21,11 +21,9 @@
 #include "classfile.hxx"
 
 #include <codemaker/global.hxx>
-#include <codemaker/options.hxx>
 #include <codemaker/unotype.hxx>
 
 #include <osl/diagnose.h>
-#include <rtl/string.h>
 #include <rtl/string.hxx>
 #include <sal/types.h>
 
diff --git a/codemaker/source/javamaker/javamaker.cxx b/codemaker/source/javamaker/javamaker.cxx
index 4c15f4c1e78b..3ba8da38b2dc 100644
--- a/codemaker/source/javamaker/javamaker.cxx
+++ b/codemaker/source/javamaker/javamaker.cxx
@@ -22,7 +22,6 @@
 #include <cstdlib>
 #include <cstring>
 #include <iostream>
-#include <vector>
 
 #include <codemaker/generatedtypeset.hxx>
 #include <codemaker/typemanager.hxx>
diff --git a/codemaker/source/javamaker/javaoptions.cxx b/codemaker/source/javamaker/javaoptions.cxx
index 4db26c1bbd23..1be9df89e146 100644
--- a/codemaker/source/javamaker/javaoptions.cxx
+++ b/codemaker/source/javamaker/javaoptions.cxx
@@ -20,8 +20,6 @@
 #include <stdio.h>
 #include <string.h>
 #include "javaoptions.hxx"
-#include <osl/process.h>
-#include <osl/thread.h>
 
 
 #ifdef SAL_UNX
diff --git a/codemaker/source/javamaker/javatype.cxx b/codemaker/source/javamaker/javatype.cxx
index 974a8f31be6b..6939b4bb0f75 100644
--- a/codemaker/source/javamaker/javatype.cxx
+++ b/codemaker/source/javamaker/javatype.cxx
@@ -33,7 +33,6 @@
 #include <codemaker/exceptiontree.hxx>
 #include <codemaker/generatedtypeset.hxx>
 #include <codemaker/global.hxx>
-#include <codemaker/options.hxx>
 #include <codemaker/typemanager.hxx>
 #include <codemaker/unotype.hxx>
 #include <codemaker/commonjava.hxx>
diff --git a/codemaker/source/javamaker/javatype.hxx b/codemaker/source/javamaker/javatype.hxx
index 9df1d94b5179..520ca1175c42 100644
--- a/codemaker/source/javamaker/javatype.hxx
+++ b/codemaker/source/javamaker/javatype.hxx
@@ -22,9 +22,9 @@
 #include <sal/config.h>
 
 #include <rtl/ref.hxx>
+#include <rtl/ustring.hxx>
 
 namespace codemaker { class GeneratedTypeSet; }
-namespace rtl { class OUString; }
 class JavaOptions;
 class TypeManager;
 
diff --git a/codemaker/source/netmaker/csharpfile.hxx b/codemaker/source/netmaker/csharpfile.hxx
index 6bdc430552dc..56ba30429435 100644
--- a/codemaker/source/netmaker/csharpfile.hxx
+++ b/codemaker/source/netmaker/csharpfile.hxx
@@ -14,6 +14,8 @@
 #include <string>
 #include <string_view>
 
+#include <codemaker/typemanager.hxx>
+
 class CSharpFile
 {
 public:
diff --git a/codemaker/source/netmaker/netoptions.cxx b/codemaker/source/netmaker/netoptions.cxx
index 5050bc7fde28..67805f786242 100644
--- a/codemaker/source/netmaker/netoptions.cxx
+++ b/codemaker/source/netmaker/netoptions.cxx
@@ -8,7 +8,6 @@
  */
 
 #include <iostream>
-#include <string>
 
 #include "netoptions.hxx"
 
diff --git a/codemaker/source/netmaker/netproduce.cxx b/codemaker/source/netmaker/netproduce.cxx
index ef044c99fb2a..c91a82696ff8 100644
--- a/codemaker/source/netmaker/netproduce.cxx
+++ b/codemaker/source/netmaker/netproduce.cxx
@@ -10,7 +10,6 @@
 #include <iostream>
 #include <vector>
 
-#include <codemaker/codemaker.hxx>
 #include <o3tl/string_view.hxx>
 #include <rtl/strbuf.hxx>
 #include <unoidl/unoidl.hxx>