diff --git a/src/perl/perl-common.c b/src/perl/perl-common.c
index a3a599ac..cad117fc 100644
--- a/src/perl/perl-common.c
+++ b/src/perl/perl-common.c
@@ -219,12 +219,12 @@ char *perl_get_use_list(void)
         return ret;
 }
 
-void irssi_callXS(void (*subaddr)(CV* cv), CV *cv, SV **mark)
+void irssi_callXS(void (*subaddr)(pTHX_ CV* cv), CV *cv, SV **mark)
 {
 	dSP;
 
 	PUSHMARK(mark);
-	(*subaddr)(cv);
+	(*subaddr)(aTHX_ cv);
 
 	PUTBACK;
 }
diff --git a/src/perl/perl-common.h b/src/perl/perl-common.h
index 9fa85f07..50469942 100644
--- a/src/perl/perl-common.h
+++ b/src/perl/perl-common.h
@@ -32,6 +32,10 @@ SV *perl_func_sv_inc(SV *func, const char *package);
 extern STRLEN PL_na;
 #endif
 
+#ifndef pTHX_
+#  define pTHX_
+#endif
+
 #define iobject_bless(object) \
 	((object) == NULL ? &PL_sv_undef : \
 	irssi_bless_iobject((object)->type, (object)->chat_type, object))
@@ -57,10 +61,10 @@ void irssi_add_plains(PLAIN_OBJECT_INIT_REC *objects);
 char *perl_get_use_list(void);
 
 #define irssi_boot(x) { \
-	extern void boot_Irssi__##x(CV *cv); \
+	extern void boot_Irssi__##x(pTHX_ CV *cv); \
 	irssi_callXS(boot_Irssi__##x, cv, mark); \
 	}
-void irssi_callXS(void (*subaddr)(CV* cv), CV *cv, SV **mark);
+void irssi_callXS(void (*subaddr)(pTHX_ CV* cv), CV *cv, SV **mark);
 
 void perl_common_start(void);
 void perl_common_stop(void);
diff --git a/src/perl/perl-core.c b/src/perl/perl-core.c
index 0c1e506b..2d300289 100644
--- a/src/perl/perl-core.c
+++ b/src/perl/perl-core.c
@@ -84,7 +84,7 @@ static void perl_script_destroy(PERL_SCRIPT_REC *script)
         g_free(script);
 }
 
-extern void boot_DynaLoader(CV* cv);
+extern void boot_DynaLoader(pTHX_ CV* cv);
 
 #if PERL_STATIC_LIBS == 1
 extern void boot_Irssi(CV *cv);
@@ -101,7 +101,7 @@ XS(boot_Irssi_Core)
 }
 #endif
 
-static void xs_init(void)
+static void xs_init(pTHX)
 {
 	dXSUB_SYS;