diff --git a/include/cryb/test.h b/include/cryb/test.h
index b784014..1b92eb5 100644
--- a/include/cryb/test.h
+++ b/include/cryb/test.h
@@ -82,6 +82,8 @@ void t_fcloseall(void);
 /*
  * Various utilities
  */
+int t_is_null(const void *);
+int t_is_not_null(const void *);
 int t_compare_mem(const void *, const void *, size_t);
 int t_compare_str(const char *, const char *);
 #define t_compare_num(n, t) int t_compare_##n(t, t);
diff --git a/lib/test/t_main.c b/lib/test/t_main.c
index 9c501b0..ba293fe 100644
--- a/lib/test/t_main.c
+++ b/lib/test/t_main.c
@@ -170,6 +170,16 @@ t_run_test(struct t_test *t, int n)
 	ret = 0;
 	if ((signo = setjmp(sigjmp)) == 0)
 		ret = (*t->func)(&desc, t->arg);
+	if (t_malloc_fail != 0) {
+		t_verbose("WARNING: test case left t_malloc_fail = %d\n",
+		    t_malloc_fail);
+		t_malloc_fail = 0;
+	}
+	if (t_malloc_fail_after != 0) {
+		t_verbose("WARNING: test case left t_malloc_fail_after = %d\n",
+		    t_malloc_fail_after);
+		t_malloc_fail_after = 0;
+	}
 	if (ret > 0)
 		printf("ok %d - %s\n", n, desc ? desc : "no description");
 	else if (ret < 0)
diff --git a/lib/test/t_malloc.c b/lib/test/t_malloc.c
index 50fd06b..d4f75c8 100644
--- a/lib/test/t_malloc.c
+++ b/lib/test/t_malloc.c
@@ -126,7 +126,7 @@ static struct bucket buckets[BUCKET_MAX_SHIFT + 1];
 
 /* mapping metadata */
 static struct mapping *mappings;
-unsigned long nmapalloc, nmapfree;
+static unsigned long nmapalloc, nmapfree;
 
 /* if non-zero, all allocations fail */
 int t_malloc_fail;
diff --git a/lib/test/t_util.c b/lib/test/t_util.c
index ed4260b..025cdeb 100644
--- a/lib/test/t_util.c
+++ b/lib/test/t_util.c
@@ -40,6 +40,34 @@
 
 #include <cryb/test.h>
 
+/*
+ * Print a verbose message if a pointer is not null.
+ */
+int
+t_is_null(const void *ptr)
+{
+
+	if (ptr != NULL) {
+		t_verbose("expected null pointer, got non-null pointer\n");
+		return (0);
+	}
+	return (1);
+}
+
+/*
+ * Print a verbose message if a pointer is null.
+ */
+int
+t_is_not_null(const void *ptr)
+{
+
+	if (ptr == NULL) {
+		t_verbose("expected non-null pointer, got null pointer\n");
+		return (0);
+	}
+	return (1);
+}
+
 /*
  * Compare two buffers, and print a verbose message if they differ.
  */