diff -ur cfitsio-3.47/configure cfitsio-3.47.soname/configure
--- cfitsio-3.47/configure	2019-08-01 15:59:50.735018203 +0200
+++ cfitsio-3.47.soname/configure	2019-08-01 16:04:16.277042668 +0200
@@ -2293,7 +2293,7 @@
 CFITSIO_MINOR=47
 
 # Increment soname each time the interface changes:
-CFITSIO_SONAME=8
+CFITSIO_SONAME=7
 
 
 #--------------------------------------------------------------------
diff -ur cfitsio-3.47/configure.in cfitsio-3.47.soname/configure.in
--- cfitsio-3.47/configure.in	2019-05-21 21:42:37.000000000 +0200
+++ cfitsio-3.47.soname/configure.in	2019-08-01 16:03:15.723124934 +0200
@@ -17,7 +17,7 @@
 AC_SUBST(CFITSIO_MAJOR,3)
 AC_SUBST(CFITSIO_MINOR,47)
 # Increment soname each time the interface changes:
-AC_SUBST(CFITSIO_SONAME,8)
+AC_SUBST(CFITSIO_SONAME,7)
 
 #--------------------------------------------------------------------
 # Command options
diff -ur cfitsio-3.47/fitsio.h cfitsio-3.47.soname/fitsio.h
--- cfitsio-3.47/fitsio.h	2019-05-08 17:34:50.000000000 +0200
+++ cfitsio-3.47.soname/fitsio.h	2019-08-01 16:05:22.684049113 +0200
@@ -37,7 +37,7 @@
 #define CFITSIO_VERSION 3.47
 #define CFITSIO_MINOR 47
 #define CFITSIO_MAJOR 3
-#define CFITSIO_SONAME 8
+#define CFITSIO_SONAME 7
 
 /* the SONAME is incremented in a new release if the binary shared */
 /* library (on linux and Mac systems) is not backward compatible */