diff --git a/include/jemalloc/internal/util.h b/include/jemalloc/internal/util.h
index b8885bfa..6e214702 100644
--- a/include/jemalloc/internal/util.h
+++ b/include/jemalloc/internal/util.h
@@ -106,9 +106,9 @@ void	malloc_write(const char *s);
  * malloc_vsnprintf() supports a subset of snprintf(3) that avoids floating
  * point math.
  */
-int	malloc_vsnprintf(char *str, size_t size, const char *format,
+size_t	malloc_vsnprintf(char *str, size_t size, const char *format,
     va_list ap);
-int	malloc_snprintf(char *str, size_t size, const char *format, ...)
+size_t	malloc_snprintf(char *str, size_t size, const char *format, ...)
     JEMALLOC_FORMAT_PRINTF(3, 4);
 void	malloc_vcprintf(void (*write_cb)(void *, const char *), void *cbopaque,
     const char *format, va_list ap);
diff --git a/src/util.c b/src/util.c
index 02673c70..982a2e31 100644
--- a/src/util.c
+++ b/src/util.c
@@ -314,10 +314,9 @@ x2s(uintmax_t x, bool alt_form, bool uppercase, char *s, size_t *slen_p)
 	return (s);
 }
 
-int
+size_t
 malloc_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 {
-	int ret;
 	size_t i;
 	const char *f;
 
@@ -585,21 +584,19 @@ malloc_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 		str[i] = '\0';
 	else
 		str[size - 1] = '\0';
-	assert(i < INT_MAX);
-	ret = (int)i;
 
 #undef APPEND_C
 #undef APPEND_S
 #undef APPEND_PADDED_S
 #undef GET_ARG_NUMERIC
-	return (ret);
+	return (i);
 }
 
 JEMALLOC_FORMAT_PRINTF(3, 4)
-int
+size_t
 malloc_snprintf(char *str, size_t size, const char *format, ...)
 {
-	int ret;
+	size_t ret;
 	va_list ap;
 
 	va_start(ap, format);
diff --git a/test/src/timer.c b/test/src/timer.c
index e91b3cf2..3c7e63a2 100644
--- a/test/src/timer.c
+++ b/test/src/timer.c
@@ -32,9 +32,8 @@ timer_ratio(timedelta_t *a, timedelta_t *b, char *buf, size_t buflen)
 	uint64_t t0 = timer_usec(a);
 	uint64_t t1 = timer_usec(b);
 	uint64_t mult;
-	unsigned i = 0;
-	unsigned j;
-	int n;
+	size_t i = 0;
+	size_t j, n;
 
 	/* Whole. */
 	n = malloc_snprintf(&buf[i], buflen-i, "%"FMTu64, t0 / t1);
diff --git a/test/unit/bitmap.c b/test/unit/bitmap.c
index 1ab0bb8e..a2dd5463 100644
--- a/test/unit/bitmap.c
+++ b/test/unit/bitmap.c
@@ -101,7 +101,7 @@ TEST_BEGIN(test_bitmap_sfu)
 		bitmap_info_t binfo;
 		bitmap_info_init(&binfo, i);
 		{
-			ssize_t j;
+			size_t j;
 			bitmap_t *bitmap = (bitmap_t *)malloc(
 			    bitmap_size(&binfo));
 			bitmap_init(bitmap, &binfo);
@@ -119,7 +119,7 @@ TEST_BEGIN(test_bitmap_sfu)
 			 * Iteratively unset bits starting at the end, and
 			 * verify that bitmap_sfu() reaches the unset bits.
 			 */
-			for (j = i - 1; j >= 0; j--) {
+			for (j = i - 1; j < i; j--) { /* (i..0] */
 				bitmap_unset(bitmap, &binfo, j);
 				assert_zd_eq(bitmap_sfu(bitmap, &binfo), j,
 				    "First unset bit should the bit previously "
diff --git a/test/unit/util.c b/test/unit/util.c
index 2f65aad2..d24c1c79 100644
--- a/test/unit/util.c
+++ b/test/unit/util.c
@@ -160,14 +160,14 @@ TEST_BEGIN(test_malloc_snprintf_truncated)
 {
 #define	BUFLEN	15
 	char buf[BUFLEN];
-	int result;
+	size_t result;
 	size_t len;
 #define TEST(expected_str_untruncated, ...) do {			\
 	result = malloc_snprintf(buf, len, __VA_ARGS__);		\
 	assert_d_eq(strncmp(buf, expected_str_untruncated, len-1), 0,	\
 	    "Unexpected string inequality (\"%s\" vs \"%s\")",		\
 	    buf, expected_str_untruncated);		\
-	assert_d_eq(result, strlen(expected_str_untruncated),		\
+	assert_zu_eq(result, strlen(expected_str_untruncated),		\
 	    "Unexpected result");					\
 } while (0)
 
@@ -193,11 +193,11 @@ TEST_BEGIN(test_malloc_snprintf)
 {
 #define	BUFLEN	128
 	char buf[BUFLEN];
-	int result;
+	size_t result;
 #define	TEST(expected_str, ...) do {					\
 	result = malloc_snprintf(buf, sizeof(buf), __VA_ARGS__);	\
 	assert_str_eq(buf, expected_str, "Unexpected output");		\
-	assert_d_eq(result, strlen(expected_str), "Unexpected result");	\
+	assert_zu_eq(result, strlen(expected_str), "Unexpected result");\
 } while (0)
 
 	TEST("hello", "hello");