diff --git a/src/tests.c b/src/tests.c
index d496ac91..d8664fbe 100644
--- a/src/tests.c
+++ b/src/tests.c
@@ -52,7 +52,8 @@ static void _test_nop(const tf_test_options_t* options)
 	_write_file("out/test.js", "print('hi');");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -65,7 +66,8 @@ static void _test_exception(const tf_test_options_t* options)
 	_write_file("out/test.js", "throw new Error('oops');");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("result = %d\n", result);
@@ -98,7 +100,8 @@ static void _test_sandbox(const tf_test_options_t* options)
 		"exit(r);\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -130,7 +133,8 @@ static void _test_child(const tf_test_options_t* options)
 		"exit(0);\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -168,7 +172,8 @@ static void _test_promise(const tf_test_options_t* options)
 		"}\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -210,7 +215,8 @@ static void _test_promise_remote_throw(const tf_test_options_t* options)
 		"}\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -254,7 +260,8 @@ static void _test_promise_remote_reject(const tf_test_options_t* options)
 		"}\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -331,7 +338,8 @@ static void _test_this(const tf_test_options_t* options)
 		"exit(0);\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -361,7 +369,8 @@ static void _test_await(const tf_test_options_t* options)
 		"\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -391,14 +400,16 @@ static void _test_import(const tf_test_options_t* options)
 		"}\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
 	assert(WIFEXITED(result));
 	assert(WEXITSTATUS(result) == 0);
 
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/bad.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/bad.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -416,7 +427,8 @@ static void _test_exit(const tf_test_options_t* options)
 	_write_file("out/blah.js", "\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -434,7 +446,8 @@ static void _test_icu(const tf_test_options_t* options)
 		"print(parseInt('3').toLocaleString());\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -482,7 +495,8 @@ static void _test_uint8array(const tf_test_options_t* options)
 		"}\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -523,7 +537,8 @@ static void _test_float(const tf_test_options_t* options)
 		"print(\"child ready\");\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	(void)result;
@@ -610,7 +625,8 @@ static void _test_socket(const tf_test_options_t* options)
 		"});\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));
@@ -659,7 +675,8 @@ static void _test_b64(const tf_test_options_t* options)
 		"}\n");
 
 	char command[256];
-	snprintf(command, sizeof(command), "%s run --db-path=:memory: -s out/test.js" TEST_ARGS, options->exe_path);
+	unlink("out/test_db0.sqlite");
+	snprintf(command, sizeof(command), "%s run --db-path=out/test_db0.sqlite -s out/test.js" TEST_ARGS, options->exe_path);
 	tf_printf("%s\n", command);
 	int result = system(command);
 	tf_printf("returned %d\n", WEXITSTATUS(result));