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
@@ -34,6 +34,7 @@ target_include_directories(SoundTouch PU
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
 )
+set_target_properties(SoundTouch PROPERTIES VERSION 1.0.0 SOVERSION 1)
 
 target_compile_definitions(SoundTouch PRIVATE ${COMPILE_DEFINITIONS})
 target_compile_options(SoundTouch PRIVATE ${COMPILE_OPTIONS})
@@ -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}")