diff --git a/tests/suites/test_suite_ecdsa.function b/tests/suites/test_suite_ecdsa.function
index 01eeb8e..a8b1e45 100644
--- a/tests/suites/test_suite_ecdsa.function
+++ b/tests/suites/test_suite_ecdsa.function
@@ -5,6 +5,7 @@
     ( !defined(MBEDTLS_ECDSA_DETERMINISTIC) && defined(MBEDTLS_HAS_ALG_SHA_256_VIA_LOWLEVEL_OR_PSA) )
 #define MBEDTLS_HAS_ALG_SHA_256_VIA_MD_IF_DETERMINISTIC
 #endif
+#define MBEDTLS_TEST_HASH_MAX_SIZE 64
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -19,7 +20,7 @@
     mbedtls_ecp_point Q;
     mbedtls_mpi d, r, s;
     mbedtls_test_rnd_pseudo_info rnd_info;
-    unsigned char buf[MBEDTLS_MD_MAX_SIZE];
+    unsigned char buf[MBEDTLS_TEST_HASH_MAX_SIZE];
 
     mbedtls_ecp_group_init( &grp );
     mbedtls_ecp_point_init( &Q );
@@ -51,7 +52,7 @@
     mbedtls_ecp_point Q;
     mbedtls_mpi d, r, s;
     mbedtls_test_rnd_pseudo_info rnd_info;
-    unsigned char buf[MBEDTLS_MD_MAX_SIZE];
+    unsigned char buf[MBEDTLS_TEST_HASH_MAX_SIZE];
 
     mbedtls_ecp_group_init( &grp );
     mbedtls_ecp_point_init( &Q );