diff '--color=auto' -rupN soundtouch.orig/CMakeLists.txt soundtouch/CMakeLists.txt
--- soundtouch.orig/CMakeLists.txt	2021-08-26 13:11:17.958981063 +0200
+++ soundtouch/CMakeLists.txt	2021-08-26 13:16:35.308990428 +0200
@@ -121,6 +122,10 @@ endif()
 
 ########################
 
+# autotools
+install(FILES include/soundtouch_config.h DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/soundtouch")
+install(FILES soundtouch.m4 DESTINATION "${CMAKE_INSTALL_DATADIR}/aclocal")
+
 # pkgconfig
 set(prefix "${CMAKE_INSTALL_PREFIX}")
 set(execprefix "\${prefix}")