diff --git a/src/cxx/configure.ac b/src/cxx/configure.ac
index 63f05d7..e284f0d 100644
--- a/src/cxx/configure.ac
+++ b/src/cxx/configure.ac
@@ -175,7 +175,7 @@ CXXCFLAGS_NO_C="$CXXCFLAGS $CPPFLAGS"
 LDCCFLAGS="$LDFLAGS $CCFLAGS"
 LDCXXFLAGS="$LDFLAGS $CXXCFLAGS"
 
-AC_CHECK_LIB([cfitsio],[ffgnrwll],,AC_MSG_ERROR([could not find the cfitsio library]),[-lm])
+AC_CHECK_LIB([cfitsio -lz],[ffgnrwll],,AC_MSG_ERROR([could not find the cfitsio library]),[-lm -lz])
 AC_CHECK_HEADERS([fitsio.h],,AC_MSG_ERROR([could not find the cfitsio header file]),)
 
 AC_SUBST(SILENT_RULE)