diff --git a/ports/pthreads/CMakeLists.txt b/ports/pthreads/CMakeLists.txt
index d6eed5310..7ae6bcc34 100644
--- a/ports/pthreads/CMakeLists.txt
+++ b/ports/pthreads/CMakeLists.txt
@@ -3,7 +3,6 @@ cmake_minimum_required(VERSION 3.9.0)
 project(pthreads)
 
 set(PTHREAD_PUBLIC_HEADERS pthread.h sched.h semaphore.h)
-set(PTHREAD_PRIVATE_HEADERS config.h implement.h need_errno.h)
 
 set(PTHREAD_SHARED_SOURCES
   autostatic.c
@@ -171,7 +170,7 @@ set(PTHREAD_STATIC_SOURCES
 
 
 option(PTW32_ARCH  "x32")
-add_definitions(-DPTW32_ARCH=${PTW32_ARCH} -DDPTW32_RC_MSC -DHAVE_PTW32_CONFIG_H -D_TIMESPEC_DEFINED)
+add_definitions(-DPTW32_ARCH=${PTW32_ARCH} -DPTW32_RC_MSC -DHAVE_PTW32_CONFIG_H -D_TIMESPEC_DEFINED)
 
 if(BUILD_SHARED_LIBS)
   set(PTHREAD_SOURCES  ${PTHREAD_SHARED_SOURCES})
@@ -188,6 +187,7 @@ if(PTHREADS_BUILD_CPP)
 elseif(PTHREADS_BUILD_SEH)
   set(PTHREADS_EXCEPTION_SCHEME SE)
   add_definitions(/__CLEANUP_SEH)
+else()
   set(PTHREADS_EXCEPTION_SCHEME C)
 endif()
 
diff --git a/ports/pthreads/portfile.cmake b/ports/pthreads/portfile.cmake
index 813554a87..cabf8a39b 100644
--- a/ports/pthreads/portfile.cmake
+++ b/ports/pthreads/portfile.cmake
@@ -23,7 +23,8 @@ vcpkg_copy_pdbs()
 file(GLOB HEADERS "${CURRENT_PACKAGES_DIR}/include/*.h")
 foreach(HEADER ${HEADERS})
   file(READ "${HEADER}" _contents)
-  string(REPLACE "!defined(_TIMESPEC_DEFINED)" "0" _contents "${_contents}")
+  string(REPLACE "defined(_TIMESPEC_DEFINED)" "1" _contents "${_contents}")
+  string(REPLACE "defined(PTW32_RC_MSC)" "1" _contents "${_contents}")
   if(VCPKG_LIBRARY_LINKAGE STREQUAL static)
     string(REPLACE "!defined(PTW32_STATIC_LIB)" "0" _contents "${_contents}")
   endif()