diff --git a/test/xmss_open.c b/test/xmss_open.c
index 05ec8fe..a809514 100644
--- a/test/xmss_open.c
+++ b/test/xmss_open.c
@@ -12,7 +12,7 @@ int main(int argc, char **argv) {
 
     if (argc != 2) {
         fprintf(stderr, "Expected keypair filename as only parameter, "
-                        "and the message + signature via stdin.\n"
+                        "and the signature + message via stdin.\n"
                         "Keypair file needs only to contain the public key.\n"
                         "The return code 0 indicates verification success.\n");
         return -1;
diff --git a/test/xmss_sign.c b/test/xmss_sign.c
index 13c0615..8fa1331 100644
--- a/test/xmss_sign.c
+++ b/test/xmss_sign.c
@@ -18,7 +18,7 @@ int main(int argc, char **argv) {
         return -1;
     }
 
-    keypair = fopen(argv[1], "rb");
+    keypair = fopen(argv[1], "r+b");
     if (keypair == NULL) {
         fprintf(stderr, "Could not open keypair file.\n");
         return -1;
diff --git a/test/xmssmt_open.c b/test/xmssmt_open.c
index 2636f95..323eaac 100644
--- a/test/xmssmt_open.c
+++ b/test/xmssmt_open.c
@@ -12,7 +12,7 @@ int main(int argc, char **argv) {
 
     if (argc != 2) {
         fprintf(stderr, "Expected keypair filename as only parameter, "
-                        "and the message + signature via stdin.\n"
+                        "and the signature + message via stdin.\n"
                         "Keypair file needs only to contain the public key.\n"
                         "The return code 0 indicates verification success.\n");
         return -1;
diff --git a/test/xmssmt_sign.c b/test/xmssmt_sign.c
index f709366..a136430 100644
--- a/test/xmssmt_sign.c
+++ b/test/xmssmt_sign.c
@@ -18,7 +18,7 @@ int main(int argc, char **argv) {
         return -1;
     }
 
-    keypair = fopen(argv[1], "rb");
+    keypair = fopen(argv[1], "r+b");
     if (keypair == NULL) {
         fprintf(stderr, "Could not open keypair file.\n");
         return -1;