diff --git a/src/tests/tests.c b/src/tests/tests.c
index 8ccb2ce4..5e8b6b6a 100644
--- a/src/tests/tests.c
+++ b/src/tests/tests.c
@@ -51,8 +51,8 @@ unsigned int MOTO_MAP_pack(byte * packed, const byte * unpacked, unsigned int un
 int Test_MOTO_MAP_pack(char * errmsg)
 {
   unsigned int i, j;
-  byte buffer[1024];
-  byte buffer2[1024];
+  byte buffer[256];
+  byte buffer2[256];
   unsigned int packed_len, unpacked_len, original_len;
   static const char * tests[] = {
     "12345AAAAAAA@",    // best : 00 05 "12345" 07 'A' 01 '@' : 11
diff --git a/src/tests/tests.h b/src/tests/tests.h
index 088a9480..7b51af5c 100644
--- a/src/tests/tests.h
+++ b/src/tests/tests.h
@@ -22,7 +22,7 @@
 #ifndef TESTS_H_INCLUDED
 #define TESTS_H_INCLUDED
 
-#define ERRMSG_LENGTH (256)
+#define ERRMSG_LENGTH (512)
 
 #define TEST(func) int Test_ ## func (char *);
 #include "testlist.h"