diff --git a/src/common.h b/src/common.h
index 0cf951b3..966e28d0 100644
--- a/src/common.h
+++ b/src/common.h
@@ -6,6 +6,8 @@
 #define IRSSI_GLOBAL_CONFIG "irssi.conf" /* config file name in /etc/ */
 #define IRSSI_HOME_CONFIG "config" /* config file name in ~/.irssi/ */
 
+#define IRSSI_ABI_VERSION 1
+
 #define DEFAULT_SERVER_ADD_PORT 6667
 
 #ifdef HAVE_CONFIG_H
diff --git a/src/core/expandos.c b/src/core/expandos.c
index 1fc517af..67aea837 100644
--- a/src/core/expandos.c
+++ b/src/core/expandos.c
@@ -414,6 +414,13 @@ static char *expando_releasetime(SERVER_REC *server, void *item, int *free_ret)
 	return g_strdup_printf("%04d", IRSSI_VERSION_TIME);
 }
 
+/* client abi */
+static char *expando_abiversion(SERVER_REC *server, void *item, int *free_ret)
+{
+        *free_ret = TRUE;
+	return g_strdup_printf("%d", IRSSI_ABI_VERSION);
+}
+
 /* current working directory */
 static char *expando_workdir(SERVER_REC *server, void *item, int *free_ret)
 {
@@ -658,6 +665,8 @@ void expandos_init(void)
 		       "", EXPANDO_NEVER, NULL);
 	expando_create("versiontime", expando_releasetime,
 		       "", EXPANDO_NEVER, NULL);
+	expando_create("abiversion", expando_abiversion,
+		       "", EXPANDO_NEVER, NULL);
 	expando_create("W", expando_workdir, NULL);
 	expando_create("Y", expando_realname,
 		       "window changed", EXPANDO_ARG_NONE,
diff --git a/src/core/modules-load.c b/src/core/modules-load.c
index 6086d9ae..9baac1d7 100644
--- a/src/core/modules-load.c
+++ b/src/core/modules-load.c
@@ -160,11 +160,14 @@ static int module_load_name(const char *path, const char *rootmodule,
 {
 	void (*module_init) (void);
 	void (*module_deinit) (void);
+	void (*module_version) (int *);
 	GModule *gmodule;
         MODULE_REC *module;
 	MODULE_FILE_REC *rec;
+	gpointer value_version = NULL;
 	gpointer value1, value2 = NULL;
-	char *initfunc, *deinitfunc;
+	char *versionfunc, *initfunc, *deinitfunc;
+	int module_abi_version = 0;
         int found;
 
 	gmodule = module_open(path, &found);
@@ -176,6 +179,27 @@ static int module_load_name(const char *path, const char *rootmodule,
 		return found ? 0 : -1;
 	}
 
+	/* get the module's irssi abi version and bail out on mismatch */
+	versionfunc = module_get_func(rootmodule, submodule, "abicheck");
+	if (!g_module_symbol(gmodule, versionfunc, &value_version)) {
+		g_free(versionfunc);
+		module_error(MODULE_ERROR_VERSION_MISMATCH, "0",
+			     rootmodule, submodule);
+		g_module_close(gmodule);
+		return 0;
+	}
+	g_free(versionfunc);
+	module_version = value_version;
+	module_version(&module_abi_version);
+	if (module_abi_version != IRSSI_ABI_VERSION) {
+		char *module_abi_versionstr = g_strdup_printf("%d", module_abi_version);
+		module_error(MODULE_ERROR_VERSION_MISMATCH, module_abi_versionstr,
+			     rootmodule, submodule);
+		g_free(module_abi_versionstr);
+		g_module_close(gmodule);
+		return 0;
+	}
+
 	/* get the module's init() and deinit() functions */
 	initfunc = module_get_func(rootmodule, submodule, "init");
 	deinitfunc = module_get_func(rootmodule, submodule, "deinit");
diff --git a/src/core/modules.h b/src/core/modules.h
index 75a77c77..b2fa2fa4 100644
--- a/src/core/modules.h
+++ b/src/core/modules.h
@@ -27,6 +27,7 @@
 enum {
 	MODULE_ERROR_ALREADY_LOADED,
 	MODULE_ERROR_LOAD,
+	MODULE_ERROR_VERSION_MISMATCH,
 	MODULE_ERROR_INVALID
 };
 
diff --git a/src/fe-common/core/fe-modules.c b/src/fe-common/core/fe-modules.c
index df97ceb1..27b6b4c1 100644
--- a/src/fe-common/core/fe-modules.c
+++ b/src/fe-common/core/fe-modules.c
@@ -43,6 +43,10 @@ static void sig_module_error(void *number, const char *data,
 		printformat(NULL, NULL, MSGLEVEL_CLIENTERROR,
 			    TXT_MODULE_LOAD_ERROR, rootmodule, submodule, data);
 		break;
+	case MODULE_ERROR_VERSION_MISMATCH:
+		printformat(NULL, NULL, MSGLEVEL_CLIENTERROR,
+			    TXT_MODULE_VERSION_MISMATCH, rootmodule, submodule, data);
+		break;
 	case MODULE_ERROR_INVALID:
 		printformat(NULL, NULL, MSGLEVEL_CLIENTERROR,
 			    TXT_MODULE_INVALID, rootmodule, submodule);
diff --git a/src/fe-common/core/module-formats.c b/src/fe-common/core/module-formats.c
index 4ae26950..e6d32b6d 100644
--- a/src/fe-common/core/module-formats.c
+++ b/src/fe-common/core/module-formats.c
@@ -196,6 +196,7 @@ FORMAT_REC fecommon_core_formats[] = {
 	{ "module_already_loaded", "Module {hilight $0/$1} already loaded", 2, { 0, 0 } },
 	{ "module_not_loaded", "Module {hilight $0/$1} is not loaded", 2, { 0, 0 } },
 	{ "module_load_error", "Error loading module {hilight $0/$1}: $2", 3, { 0, 0, 0 } },
+	{ "module_version_mismatch", "{hilight $0/$1} is ABI version $2 but Irssi is version $abiversion, cannot load", 3, { 0, 0, 0 } },
 	{ "module_invalid", "{hilight $0/$1} isn't Irssi module", 2, { 0, 0 } },
 	{ "module_loaded", "Loaded module {hilight $0/$1}", 2, { 0, 0 } },
 	{ "module_unloaded", "Unloaded module {hilight $0/$1}", 2, { 0, 0 } },
diff --git a/src/fe-common/core/module-formats.h b/src/fe-common/core/module-formats.h
index 18bf91f5..3f06bb97 100644
--- a/src/fe-common/core/module-formats.h
+++ b/src/fe-common/core/module-formats.h
@@ -166,6 +166,7 @@ enum {
 	TXT_MODULE_ALREADY_LOADED,
 	TXT_MODULE_NOT_LOADED,
 	TXT_MODULE_LOAD_ERROR,
+	TXT_MODULE_VERSION_MISMATCH,
 	TXT_MODULE_INVALID,
 	TXT_MODULE_LOADED,
 	TXT_MODULE_UNLOADED,
diff --git a/src/irc/proxy/proxy.c b/src/irc/proxy/proxy.c
index ce79e2b7..50a41b21 100644
--- a/src/irc/proxy/proxy.c
+++ b/src/irc/proxy/proxy.c
@@ -108,3 +108,8 @@ void irc_proxy_deinit(void)
 {
 	proxy_listen_deinit();
 }
+
+void irc_proxy_abicheck(int *version)
+{
+	*version = IRSSI_ABI_VERSION;
+}
diff --git a/src/perl/module.h b/src/perl/module.h
index 2fd15137..3cbdf3d5 100644
--- a/src/perl/module.h
+++ b/src/perl/module.h
@@ -17,4 +17,4 @@ extern PerlInterpreter *my_perl; /* must be called my_perl or some perl implemen
 
 /* Change this every time when some API changes between irssi's perl module
    (or irssi itself) and irssi's perl libraries. */
-#define IRSSI_PERL_API_VERSION 20011214
+#define IRSSI_PERL_API_VERSION (20011214 + IRSSI_ABI_VERSION)
diff --git a/src/perl/perl-core.c b/src/perl/perl-core.c
index 1a864ef7..cb690906 100644
--- a/src/perl/perl-core.c
+++ b/src/perl/perl-core.c
@@ -479,3 +479,8 @@ void perl_core_deinit(void)
 	signal_remove("script error", (SIGNAL_FUNC) sig_script_error);
 	PERL_SYS_TERM();
 }
+
+void perl_core_abicheck(int *version)
+{
+	*version = IRSSI_ABI_VERSION;
+}
diff --git a/src/perl/perl-fe.c b/src/perl/perl-fe.c
index 2abc75c0..04305b63 100644
--- a/src/perl/perl-fe.c
+++ b/src/perl/perl-fe.c
@@ -278,3 +278,8 @@ void fe_perl_deinit(void)
 
         perl_core_print_script_error(TRUE);
 }
+
+void fe_perl_abicheck(int *version)
+{
+	*version = IRSSI_ABI_VERSION;
+}