diff --git a/tests/vectors_kem.c b/tests/vectors_kem.c
index 128d5e840..6da025554 100644
--- a/tests/vectors_kem.c
+++ b/tests/vectors_kem.c
@@ -582,7 +582,9 @@ int main(int argc, char **argv) {
 err:
 	OQS_MEM_insecure_free(prng_output_stream_bytes);
 	OQS_MEM_insecure_free(kg_pk_bytes);
-	OQS_MEM_insecure_free(kg_sk_bytes);
+	if (kem != NULL) {
+		OQS_MEM_secure_free(kg_sk_bytes, kem->length_secret_key);
+	}
 
 	OQS_MEM_insecure_free(encdec_aft_c_bytes);
 	OQS_MEM_insecure_free(encdec_aft_k_bytes);
@@ -590,7 +592,9 @@ err:
 
 	OQS_MEM_insecure_free(encdec_val_c_bytes);
 	OQS_MEM_insecure_free(encdec_val_k_bytes);
-	OQS_MEM_insecure_free(encdec_val_sk_bytes);
+	if (kem != NULL) {
+		OQS_MEM_secure_free(encdec_val_sk_bytes, kem->length_secret_key);
+	}
 
 	OQS_KEM_free(kem);
 
diff --git a/tests/vectors_sig.c b/tests/vectors_sig.c
index 7dc269089..30877560e 100644
--- a/tests/vectors_sig.c
+++ b/tests/vectors_sig.c
@@ -785,12 +785,16 @@ err:
 cleanup:
 	OQS_MEM_insecure_free(prng_output_stream_bytes);
 	OQS_MEM_insecure_free(kg_pk_bytes);
-	OQS_MEM_insecure_free(kg_sk_bytes);
+	if (sig != NULL) {
+		OQS_MEM_secure_free(kg_sk_bytes, sig->length_secret_key);
+	}
 	OQS_MEM_insecure_free(sigVer_pk_bytes);
 	OQS_MEM_insecure_free(sigVer_msg_bytes);
 	OQS_MEM_insecure_free(sigVer_sig_bytes);
 	OQS_MEM_insecure_free(sigVer_ctx_bytes);
-	OQS_MEM_insecure_free(sigGen_sk_bytes);
+	if (sig != NULL) {
+		OQS_MEM_secure_free(sigGen_sk_bytes, sig->length_secret_key);
+	}
 	OQS_MEM_insecure_free(sigGen_msg_bytes);
 	OQS_MEM_insecure_free(sigGen_sig_bytes);
 	OQS_MEM_insecure_free(sigGen_ctx_bytes);