diff --git a/src/Makefile.am b/src/Makefile.am
index 0b279fb..804ffc6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -5,6 +5,7 @@ toilet_SOURCES = main.c toilet.h \
 	io.c io.h \
 	render.c render.h \
 	filter.c filter.h \
+	export.c export.h \
 	term.c figlet.c
 toilet_CFLAGS = `pkg-config --cflags cucul`
 toilet_LDFLAGS = `pkg-config --libs cucul` @GETOPT_LIBS@ @ZLIB_LIBS@
diff --git a/src/export.c b/src/export.c
new file mode 100644
index 0000000..813a521
--- /dev/null
+++ b/src/export.c
@@ -0,0 +1,58 @@
+/*
+ *  TOIlet        The Other Implementation’s letters
+ *  Copyright (c) 2006 Sam Hocevar <sam@zoy.org>
+ *                All Rights Reserved
+ *
+ *  $Id$
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the Do What The Fuck You Want To
+ *  Public License, Version 2, as published by Sam Hocevar. See
+ *  http://sam.zoy.org/wtfpl/COPYING for more details.
+ */
+
+/*
+ * This file contains export functions.
+ */
+
+#include "config.h"
+
+#if defined(HAVE_INTTYPES_H)
+#   include <inttypes.h>
+#endif
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <cucul.h>
+
+#include "toilet.h"
+#include "export.h"
+
+int export_list(void)
+{
+    char const * const * exports, * const * p;
+
+    printf("Available export formats:\n");
+
+    exports = cucul_get_export_list();
+    for(p = exports; *p; p += 2)
+        printf("\"%s\": %s\n", *p, *(p + 1));
+
+    return 0;
+}
+
+int export_set(context_t *cx, char const *format)
+{
+    char const * const * exports, * const * p;
+
+    cx->export = format;
+
+    exports = cucul_get_export_list();
+    for(p = exports; *p; p += 2)
+        if(!strcmp(*p, format))
+            return 0;
+
+    fprintf(stderr, "unknown export format `%s'\n", format);
+    return -1;
+}
+
diff --git a/src/export.h b/src/export.h
new file mode 100644
index 0000000..370b12d
--- /dev/null
+++ b/src/export.h
@@ -0,0 +1,20 @@
+/*
+ *  TOIlet        The Other Implementation’s letters
+ *  Copyright (c) 2006 Sam Hocevar <sam@zoy.org>
+ *                All Rights Reserved
+ *
+ *  $Id$
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the Do What The Fuck You Want To
+ *  Public License, Version 2, as published by Sam Hocevar. See
+ *  http://sam.zoy.org/wtfpl/COPYING for more details.
+ */
+
+/*
+ * This header defines export functions.
+ */
+
+extern int export_list(void);
+extern int export_set(context_t *, char const *);
+
diff --git a/src/main.c b/src/main.c
index e9a3531..fef4517 100644
--- a/src/main.c
+++ b/src/main.c
@@ -34,12 +34,12 @@
 #include "toilet.h"
 #include "render.h"
 #include "filter.h"
+#include "export.h"
 
 static void version(void);
 #if defined(HAVE_GETOPT_H)
 static void usage(void);
 #endif
-static int export_list(void);
 
 int main(int argc, char *argv[])
 {
@@ -138,13 +138,14 @@ int main(int argc, char *argv[])
         case 'E': /* --export */
             if(!strcmp(optarg, "list"))
                 return export_list();
-            cx->export = optarg;
+            if(export_set(cx, optarg) < 0)
+                return -1;
             break;
         case 140: /* --irc */
-            cx->export = "irc";
+            export_set(cx, "irc");
             break;
         case 141: /* --html */
-            cx->export = "html";
+            export_set(cx, "html");
             break;
         case '?':
             printf(MOREINFO, argv[0]);
@@ -260,16 +261,3 @@ static void usage(void)
 }
 #endif
 
-static int export_list(void)
-{
-    char const * const * exports, * const * p;
-
-    exports = cucul_get_export_list();
-
-    printf("Available export formats:\n");
-    for(p = exports; *p; p += 2)
-        printf("\"%s\": %s\n", *p, *(p + 1));
-
-    return 0;
-}
-