diff --git a/tests/scripts/generate_psa_wrappers.py b/tests/scripts/generate_psa_wrappers.py
index e5b4256f5e..005a324116 100755
--- a/tests/scripts/generate_psa_wrappers.py
+++ b/tests/scripts/generate_psa_wrappers.py
@@ -145,6 +145,11 @@ class PSAWrapperGenerator(c_wrapper_generator.Base):
         # Proof-of-concept: just instrument one function for now
         if function_name == 'psa_cipher_encrypt':
             return True
+        if function_name in ('psa_sign_message',
+                             'psa_verify_message',
+                             'psa_sign_hash',
+                             'psa_verify_hash'):
+            return True
         return False
 
     def _write_function_call(self, out: typing_util.Writable,
diff --git a/tests/src/psa_test_wrappers.c b/tests/src/psa_test_wrappers.c
index 3a3aaade9a..460d4535f5 100644
--- a/tests/src/psa_test_wrappers.c
+++ b/tests/src/psa_test_wrappers.c
@@ -873,7 +873,15 @@ psa_status_t mbedtls_test_wrap_psa_sign_hash(
     size_t arg5_signature_size,
     size_t *arg6_signature_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg2_hash, arg3_hash_length);
+    MBEDTLS_TEST_MEMORY_POISON(arg4_signature, arg5_signature_size);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_sign_hash)(arg0_key, arg1_alg, arg2_hash, arg3_hash_length, arg4_signature, arg5_signature_size, arg6_signature_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg2_hash, arg3_hash_length);
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg4_signature, arg5_signature_size);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }
 
@@ -918,7 +926,15 @@ psa_status_t mbedtls_test_wrap_psa_sign_message(
     size_t arg5_signature_size,
     size_t *arg6_signature_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg2_input, arg3_input_length);
+    MBEDTLS_TEST_MEMORY_POISON(arg4_signature, arg5_signature_size);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_sign_message)(arg0_key, arg1_alg, arg2_input, arg3_input_length, arg4_signature, arg5_signature_size, arg6_signature_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg2_input, arg3_input_length);
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg4_signature, arg5_signature_size);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }
 
@@ -931,7 +947,15 @@ psa_status_t mbedtls_test_wrap_psa_verify_hash(
     const uint8_t *arg4_signature,
     size_t arg5_signature_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg2_hash, arg3_hash_length);
+    MBEDTLS_TEST_MEMORY_POISON(arg4_signature, arg5_signature_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_verify_hash)(arg0_key, arg1_alg, arg2_hash, arg3_hash_length, arg4_signature, arg5_signature_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg2_hash, arg3_hash_length);
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg4_signature, arg5_signature_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }
 
@@ -974,7 +998,15 @@ psa_status_t mbedtls_test_wrap_psa_verify_message(
     const uint8_t *arg4_signature,
     size_t arg5_signature_length)
 {
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_POISON(arg2_input, arg3_input_length);
+    MBEDTLS_TEST_MEMORY_POISON(arg4_signature, arg5_signature_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     psa_status_t status = (psa_verify_message)(arg0_key, arg1_alg, arg2_input, arg3_input_length, arg4_signature, arg5_signature_length);
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg2_input, arg3_input_length);
+    MBEDTLS_TEST_MEMORY_UNPOISON(arg4_signature, arg5_signature_length);
+#endif /* defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS) */
     return status;
 }