diff --git a/haproxy.spec b/haproxy.spec
index 6b93823..e90d430 100644
--- a/haproxy.spec
+++ b/haproxy.spec
@@ -56,7 +56,7 @@ regparm_opts=
 regparm_opts="USE_REGPARM=1"
 %endif
 
-%{__make} %{?_smp_mflags} CPU="generic" TARGET="linux2628" USE_OPENSSL=1 USE_PCRE=1 USE_ZLIB=1 USE_LUA=1 ${regparm_opts} ADDINC="%{optflags}" USE_LINUX_TPROXY=1 ADDLIB="%{__global_ldflags}"
+%{__make} %{?_smp_mflags} CPU="generic" TARGET="linux2628" USE_OPENSSL=1 USE_PCRE=1 USE_ZLIB=1 USE_LUA=1 USE_CRYPT_H=1 ${regparm_opts} ADDINC="%{optflags}" USE_LINUX_TPROXY=1 ADDLIB="%{__global_ldflags}"
 
 pushd contrib/halog
 %{__make} ${halog} OPTIMIZE="%{optflags} %{build_ldflags}"
@@ -136,6 +136,7 @@ exit 0
 %changelog
 * Thu Feb  8 2018 Florian Weimer <fweimer@redhat.com> - 1.8.3-5
 - Build halog and iprange with linker flags from redhat-rpm-config
+- Tell build to include <crypt.h>
 
 * Wed Feb 07 2018 Fedora Release Engineering <releng@fedoraproject.org> - 1.8.3-4
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild