Index: head/lib/libnv/tests/dnv_tests.cc
===================================================================
--- head/lib/libnv/tests/dnv_tests.cc
+++ head/lib/libnv/tests/dnv_tests.cc
@@ -450,7 +450,7 @@
 	nvl = nvlist_create(0);
 
 	actual_val = dnvlist_take_nvlist(nvl, "123", NULL);
-	ATF_REQUIRE_EQ(actual_val, NULL);
+	ATF_REQUIRE_EQ(actual_val, static_cast<nvlist_t *>(NULL));
 
 	free(actual_val);
 	nvlist_destroy(nvl);
Index: head/lib/libnv/tests/nv_tests.cc
===================================================================
--- head/lib/libnv/tests/nv_tests.cc
+++ head/lib/libnv/tests/nv_tests.cc
@@ -54,7 +54,7 @@
 	ATF_REQUIRE(nvlist_empty(nvl));
 
 	it = NULL;
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type, &it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type, &it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(nvl);
 }
@@ -85,7 +85,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_NULL);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(nvl);
 }
@@ -118,7 +118,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_BOOL);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(nvl);
 }
@@ -153,7 +153,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_NUMBER);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(nvl);
 }
@@ -191,7 +191,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_STRING);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(nvl);
 }
@@ -237,7 +237,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_NVLIST);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(sublist);
 	nvlist_destroy(nvl);
@@ -303,7 +303,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_BINARY);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type,&it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(nvl);
 	free(value);
@@ -352,7 +352,7 @@
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(clone, &type, &it), key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_NUMBER);
-	ATF_REQUIRE_EQ(nvlist_next(clone, &type, &it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(clone, &type, &it), static_cast<const char *>(NULL));
 
 	nvlist_destroy(clone);
 	nvlist_destroy(nvl);
@@ -400,13 +400,13 @@
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(value, &type, &it),
 	    test_string_key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_STRING);
-	ATF_REQUIRE_EQ(nvlist_next(value, &type, &it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(value, &type, &it), static_cast<const char *>(NULL));
 
 	it = NULL;
 	ATF_REQUIRE_EQ(strcmp(nvlist_next(nvl, &type, &it),
 	    test_subnvlist_key), 0);
 	ATF_REQUIRE_EQ(type, NV_TYPE_NVLIST);
-	ATF_REQUIRE_EQ(nvlist_next(nvl, &type, &it), NULL);
+	ATF_REQUIRE_EQ(nvlist_next(nvl, &type, &it), static_cast<const char *>(NULL));
 }
 
 ATF_TEST_CASE_WITHOUT_HEAD(nvlist_clone__nested_nvlist);