Index: autoconf/Makefile.am
==================================================================
--- autoconf/Makefile.am
+++ autoconf/Makefile.am
@@ -1,7 +1,7 @@
 
-AM_CFLAGS = @THREADSAFE_FLAGS@ @DYNAMIC_EXTENSION_FLAGS@ @FTS5_FLAGS@ @JSON1_FLAGS@ @SESSION_FLAGS@ -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE
+AM_CFLAGS = @THREADSAFE_FLAGS@ @DYNAMIC_EXTENSION_FLAGS@ @FTS5_FLAGS@ @JSON1_FLAGS@ @ZLIB_FLAGS@ @SESSION_FLAGS@ -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE
 
 lib_LTLIBRARIES = libsqlite3.la
 libsqlite3_la_SOURCES = sqlite3.c
 libsqlite3_la_LDFLAGS = -no-undefined -version-info 8:6:8
 

Index: autoconf/configure.ac
==================================================================
--- autoconf/configure.ac
+++ autoconf/configure.ac
@@ -162,10 +162,13 @@
 fi
 AC_SUBST(EXTRA_SHELL_OBJ)
 #-----------------------------------------------------------------------
 
 AC_CHECK_FUNCS(posix_fallocate)
+AC_CHECK_HEADERS(zlib.h)
+AC_SEARCH_LIBS(deflate,z,[ZLIB_FLAGS="-DSQLITE_HAVE_ZLIB"])
+AC_SUBST(ZLIB_FLAGS)
 
 #-----------------------------------------------------------------------
 # UPDATE: Maybe it's better if users just set CFLAGS before invoking
 # configure. This option doesn't really add much...
 #