--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -117,7 +117,7 @@
 add_subdirectory(k2pdfoptlib)
 
 # ms
-add_executable(k2pdfopt k2pdfopt.c)
+add_executable(k2pdfopt k2pdfopt.c misc.c)
 target_link_libraries (k2pdfopt k2pdfoptlib willuslib ${K2PDFOPT_LIB} pthread)
 
 install(TARGETS k2pdfopt RUNTIME DESTINATION bin)
--- a/misc.c
+++ b/misc.c
@@ -0,0 +1,4 @@
+#include <k2pdfopt.h>
+#ifdef HAVE_MUPDF_LIB
+void pdf_install_load_system_font_funcs(void *p) {}
+#endif