diff --git a/CMakeLists.txt b/CMakeLists.txt
index d617e387..b4c457b4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,6 +3,8 @@ project(putty LANGUAGES C)
 
 include(cmake/setup.cmake)
 
+add_compile_definitions(HAVE_CMAKE_H)
+
 add_library(utils STATIC
   utils/base64_decode_atom.c
   utils/base64_encode_atom.c
@@ -161,8 +163,6 @@ add_executable(test_wildcard
 target_compile_definitions(test_wildcard PRIVATE TEST)
 target_link_libraries(test_wildcard utils ${platform_libraries})
 
-add_compile_definitions(HAVE_CMAKE_H)
-
 foreach(subdir ${PLATFORM_SUBDIRS})
   add_subdirectory(${subdir})
 endforeach()
diff --git a/defs.h b/defs.h
index f175d257..b8205c10 100644
--- a/defs.h
+++ b/defs.h
@@ -22,6 +22,10 @@
 #error Do not compile this code base with NDEBUG defined!
 #endif
 
+#if HAVE_CMAKE_H
+#include "cmake.h"
+#endif
+
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>                     /* for __MINGW_PRINTF_FORMAT */
diff --git a/unix/platform.h b/unix/platform.h
index 8f24b893..62f86a74 100644
--- a/unix/platform.h
+++ b/unix/platform.h
@@ -5,10 +5,6 @@
 #ifndef PUTTY_UNIX_PLATFORM_H
 #define PUTTY_UNIX_PLATFORM_H
 
-#if HAVE_CMAKE_H
-#include "cmake.h"
-#endif
-
 #include <stdio.h>                     /* for FILENAME_MAX */
 #include <stdint.h>                    /* C99 int types */
 #ifndef NO_LIBDL
diff --git a/windows/platform.h b/windows/platform.h
index 8fadf803..cd89d411 100644
--- a/windows/platform.h
+++ b/windows/platform.h
@@ -5,10 +5,6 @@
 #ifndef PUTTY_WINDOWS_PLATFORM_H
 #define PUTTY_WINDOWS_PLATFORM_H
 
-#if HAVE_CMAKE_H
-#include "cmake.h"
-#endif
-
 #include <winsock2.h>
 #include <windows.h>
 #include <stdio.h>                     /* for FILENAME_MAX */