diff --git a/src/util-io.c b/src/util-io.c
index 237114e..ad5b82a 100644
--- a/src/util-io.c
+++ b/src/util-io.c
@@ -703,6 +703,7 @@ MUNIT_TEST(test_iobuf_append_fd)
 MUNIT_TEST(test_iobuf_append_fd_too_many)
 {
 	_cleanup_fclose_ FILE *fp = tmpfile();
+	munit_assert_ptr_not_null(fp);
 	int fd = fileno(fp);
 
 	_cleanup_iobuf_ struct iobuf *buf = iobuf_new(20);
@@ -732,6 +733,7 @@ MUNIT_TEST(test_iobuf_recv_fd)
 	_cleanup_close_ int left = fds[0];
 	_cleanup_close_ int right = fds[1];
 	_cleanup_fclose_ FILE *fp = tmpfile();
+	munit_assert_ptr_not_null(fp);
 
 	/* actual message data to be sent */
 	char data[] = "some data\n";
@@ -782,7 +784,9 @@ MUNIT_TEST(test_pass_fd)
 	/* Write some data to the file on it's real fd */
 	for (size_t idx = 0; idx < ARRAY_LENGTH(fps); idx++) {
 		_cleanup_free_ char *buf = xaprintf("foo %zu\n", idx);
+		munit_assert_ptr_not_null(buf);
 		FILE *fp = fps[idx];
+		munit_assert_ptr_not_null(fp);
 		fwrite(buf, strlen(buf) + 1, 1, fp);
 		fflush(fp);
 	}
diff --git a/src/util-sources.c b/src/util-sources.c
index a3f8496..623f3a8 100644
--- a/src/util-sources.c
+++ b/src/util-sources.c
@@ -239,6 +239,7 @@ source_enable_write(struct source *source, bool enable)
 MUNIT_TEST(test_sink)
 {
 	struct sink *sink = sink_new();
+	munit_assert_ptr_not_null(sink);
 	sink_dispatch(sink);
 	sink_dispatch(sink);
 
diff --git a/src/util-strings.c b/src/util-strings.c
index d55f774..b721bd9 100644
--- a/src/util-strings.c
+++ b/src/util-strings.c
@@ -427,6 +427,7 @@ MUNIT_TEST(test_strstrip)
 	while (t->string) {
 		char *str;
 		str = strstrip(t->string, t->what);
+		munit_assert_ptr_not_null(str);
 		munit_assert_string_equal(str, t->expected);
 		free(str);
 		t++;
@@ -521,6 +522,7 @@ MUNIT_TEST(test_cmdline_as_str)
 	munit_assert_int(len, >=, 0);
 	cmdline[len] = '\0';
 
+	munit_assert_ptr_not_null(from_function);
 	munit_assert_string_equal(cmdline, from_function);
 
 	return MUNIT_OK;