diff --git a/tests/scripts/generate_psa_wrappers.py b/tests/scripts/generate_psa_wrappers.py
index a2d8787..4e8ee6c 100755
--- a/tests/scripts/generate_psa_wrappers.py
+++ b/tests/scripts/generate_psa_wrappers.py
@@ -143,6 +143,10 @@
         """Whether the specified buffer argument to a PSA function should be copied.
         """
         #pylint: disable=too-many-return-statements
+        if function_name in ('psa_sign_hash_start',
+                             'psa_sign_hash_complete',
+                             'psa_verify_hash_start'):
+            return True
         if function_name.startswith('psa_pake'):
             return True
         if function_name.startswith('psa_aead'):
diff --git a/tests/src/psa_test_wrappers.c b/tests/src/psa_test_wrappers.c
index 71ea09c..f303af8 100644
--- a/tests/src/psa_test_wrappers.c
+++ b/tests/src/psa_test_wrappers.c
@@ -1162,7 +1162,13 @@
     size_t arg2_signature_size,
     size_t *arg3_signature_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg1_signature, arg2_signature_size);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_sign_hash_complete)(arg0_operation, arg1_signature, arg2_signature_size, arg3_signature_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg1_signature, arg2_signature_size);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }
 
@@ -1174,7 +1180,13 @@
     const uint8_t *arg3_hash,
     size_t arg4_hash_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg3_hash, arg4_hash_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_sign_hash_start)(arg0_operation, arg1_key, arg2_alg, arg3_hash, arg4_hash_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg3_hash, arg4_hash_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }
 
@@ -1247,7 +1259,15 @@
     const uint8_t *arg5_signature,
     size_t arg6_signature_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg3_hash, arg4_hash_length);
+    MBEDTLS_TEST_MEMORY_POISON(arg5_signature, arg6_signature_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_verify_hash_start)(arg0_operation, arg1_key, arg2_alg, arg3_hash, arg4_hash_length, arg5_signature, arg6_signature_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg3_hash, arg4_hash_length);
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg5_signature, arg6_signature_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }