diff -up src/Makefile.am.icb src/Makefile.am
--- src/Makefile.am.icb	2020-12-07 11:40:45.000000000 +0100
+++ src/Makefile.am	2021-09-02 23:55:29.346733967 +0200
@@ -1,7 +1,7 @@
 ACLOCAL_AMFLAGS = -I m4
 
 pkgincludedir = $(includedir)/arpack
-pkginclude_HEADERS = debug.h stat.h arpackdef.h
+pkginclude_HEADERS = debug.h stat.h arpackdef.h arpackicb.h
 
 AM_DISTCHECK_CONFIGURE_FLAGS =
 if MPI