diff -bNur mod_perl2.old/Makefile mod_perl2/Makefile
--- mod_perl2.old/Makefile	2015-05-31 14:21:32.000000000 +0100
+++ mod_perl2/Makefile	2015-06-07 22:16:35.000000000 +0100
@@ -3,6 +3,7 @@
 
 PORTNAME=	mod_perl
 DISTVERSION=	2.0.9-rc2
+PORTREVISION=	1
 PORTEPOCH=	3
 CATEGORIES=	www perl5
 #MASTER_SITES=	APACHE/perl
@@ -40,6 +41,14 @@
 PLIST_SUB+=	AP22=""
 .endif
 
+# Test whether the system uses a multithreaded perl
+HAS_ITHREADS=	`${PREFIX}/bin/perl5 -e 'use Config; print $Config{useithreads} ? 1 : 0'`
+.if ${HAS_ITHREADS}
+PLIST_SUB+=	ITHREADS="@comment "
+.else
+PLIST_SUB+=	ITHREADS=""
+.endif
+
 CONFIGURE_ARGS=	PREFIX=${PREFIX} MP_APXS=${APXS} \
 		MP_APR_CONFIG=${LOCALBASE}/bin/apr-1-config
 
diff -bNur mod_perl2.old/files/patch-src-modules-perl-modperl_error.h mod_perl2/files/patch-src-modules-perl-modperl_error.h
--- mod_perl2.old/files/patch-src-modules-perl-modperl_error.h	1970-01-01 01:00:00.000000000 +0100
+++ mod_perl2/files/patch-src-modules-perl-modperl_error.h	2015-06-07 22:12:43.000000000 +0100
@@ -0,0 +1,20 @@
+--- src/modules/perl/modperl_error.h.orig 2015-05-30 19:49:12 UTC
++++ src/modules/perl/modperl_error.h
+@@ -37,6 +37,7 @@ char *modperl_error_strerror(pTHX_ apr_status_t rc);
+ 
+ void modperl_croak(pTHX_ apr_status_t rc, const char* func);
+ 
++#ifdef USE_ITHREADS
+ #define MP_PUTBACK_IF_USED() STMT_START                                 \
+     {                                                                   \
+         modperl_interp_t *interp = modperl_thx_interp_get(aTHX);        \
+@@ -44,6 +45,9 @@ void modperl_croak(pTHX_ apr_status_t rc, const char* func);
+             modperl_interp_unselect(interp);                            \
+         }                                                               \
+     } STMT_END
++#else
++#define MP_PUTBACK_IF_USED() NOOP
++#endif
+ 
+ #define MP_CROAK_PUTBACK(rc, func) STMT_START                           \
+     {                                                                   \
diff -bNur mod_perl2.old/pkg-plist mod_perl2/pkg-plist
--- mod_perl2.old/pkg-plist	2015-05-31 14:21:32.000000000 +0100
+++ mod_perl2/pkg-plist	2015-06-07 22:04:20.000000000 +0100
@@ -160,8 +160,8 @@
 %%SITE_ARCH%%/ModPerl/Const.pm
 %%SITE_ARCH%%/ModPerl/FunctionMap.pm
 %%SITE_ARCH%%/ModPerl/Global.pm
-%%SITE_ARCH%%/ModPerl/InterpPool.pm
-%%SITE_ARCH%%/ModPerl/Interpreter.pm
+%%ITHREADS%%%%SITE_ARCH%%/ModPerl/InterpPool.pm
+%%ITHREADS%%%%SITE_ARCH%%/ModPerl/Interpreter.pm
 %%SITE_ARCH%%/ModPerl/MM.pm
 %%SITE_ARCH%%/ModPerl/Manifest.pm
 %%SITE_ARCH%%/ModPerl/MapUtil.pm
@@ -177,8 +177,8 @@
 %%SITE_ARCH%%/ModPerl/StructureMap.pm
 %%SITE_ARCH%%/ModPerl/TestReport.pm
 %%SITE_ARCH%%/ModPerl/TestRun.pm
-%%SITE_ARCH%%/ModPerl/TiPool.pm
-%%SITE_ARCH%%/ModPerl/TiPoolConfig.pm
+%%ITHREADS%%%%SITE_ARCH%%/ModPerl/TiPool.pm
+%%ITHREADS%%%%SITE_ARCH%%/ModPerl/TiPoolConfig.pm
 %%SITE_ARCH%%/ModPerl/TypeMap.pm
 %%SITE_ARCH%%/ModPerl/Util.pm
 %%SITE_ARCH%%/ModPerl/WrapXS.pm
@@ -235,10 +235,10 @@
 %%SITE_ARCH%%/auto/Apache2/typemap
 %%SITE_ARCH%%/auto/ModPerl/Const/Const.so
 %%SITE_ARCH%%/auto/ModPerl/Global/Global.so
-%%SITE_ARCH%%/auto/ModPerl/InterpPool/InterpPool.so
-%%SITE_ARCH%%/auto/ModPerl/Interpreter/Interpreter.so
-%%SITE_ARCH%%/auto/ModPerl/TiPool/TiPool.so
-%%SITE_ARCH%%/auto/ModPerl/TiPoolConfig/TiPoolConfig.so
+%%ITHREADS%%%%SITE_ARCH%%/auto/ModPerl/InterpPool/InterpPool.so
+%%ITHREADS%%%%SITE_ARCH%%/auto/ModPerl/Interpreter/Interpreter.so
+%%ITHREADS%%%%SITE_ARCH%%/auto/ModPerl/TiPool/TiPool.so
+%%ITHREADS%%%%SITE_ARCH%%/auto/ModPerl/TiPoolConfig/TiPoolConfig.so
 %%SITE_ARCH%%/auto/ModPerl/Util/Util.so
 %%SITE_ARCH%%/mod_perl2.pm
 %%PERL5_MAN3%%/APR.3.gz