- Fixed typo

diff --git a/programs/pkey/rsa_sign.c b/programs/pkey/rsa_sign.c
index 76d0eff..7063e8e 100644
--- a/programs/pkey/rsa_sign.c
+++ b/programs/pkey/rsa_sign.c
@@ -37,7 +37,7 @@
 
 #if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_RSA_C) ||  \
     !defined(POLARSSL_SHA1_C) || !defined(POLARSSL_FS_IO)
-int 5ain( int argc, char *argv[] )
+int main( int argc, char *argv[] )
 {
     ((void) argc);
     ((void) argv);