diff --git a/src/base32.c b/src/base32.c
index af6a214..06a59fe 100644
--- a/src/base32.c
+++ b/src/base32.c
@@ -103,9 +103,12 @@ base32_encode(char *buf, size_t *buflen, const void *data, size_t size)
 	memset(buf, 0, *buflen);
 
 	/* how many chars can we encode within the buf */
-	maxsize = BLKSIZE_RAW * (*buflen / BLKSIZE_ENC - 1) - 1;
+	maxsize = BLKSIZE_RAW * (*buflen / BLKSIZE_ENC);
 	/* how big will the encoded data be */
-	newsize = BLKSIZE_ENC * (size / BLKSIZE_RAW + 1) + 1;
+	newsize = BLKSIZE_ENC * (size / BLKSIZE_RAW);
+	if (size % BLKSIZE_RAW) {
+		newsize += BLKSIZE_ENC;
+	}
 	/* if the buffer is too small, eat some of the data */
 	if (*buflen < newsize) {
 		size = maxsize;
@@ -132,7 +135,7 @@ base32_encode(char *buf, size_t *buflen, const void *data, size_t size)
 	/* store number of bytes from data that was used */
 	*buflen = size;
 
-	return strlen(buf) - 1;
+	return strlen(buf);
 }
 
 #define DECODE_ERROR 0xffffffff
diff --git a/tests/base32.c b/tests/base32.c
index 0b77a03..9ff0cf7 100644
--- a/tests/base32.c
+++ b/tests/base32.c
@@ -85,6 +85,48 @@ START_TEST(test_base32_5to8_8to5)
 }
 END_TEST
 
+START_TEST(test_base32_blksize)
+{
+	size_t rawlen;
+	size_t enclen;
+	char *rawbuf;
+	char *encbuf;
+	struct encoder *b32;
+	int i;
+	int val;
+
+	b32 = get_base32_encoder();
+
+	rawlen = b32->blocksize_raw();
+	enclen = b32->blocksize_encoded();
+
+	rawbuf = malloc(rawlen + 16);
+	encbuf = malloc(enclen + 16);
+
+	for (i = 0; i < rawlen; i++) {
+		rawbuf[i] = 'A';
+	}
+	rawbuf[i] = 0;
+
+	val = b32->encode(encbuf, &enclen, rawbuf, rawlen);
+
+	fail_unless(rawlen == 5, "raw length was %d not 5", rawlen);
+	fail_unless(enclen == 5, "encoded %d bytes, not 5", enclen);
+	fail_unless(val == 8, "encoded string %s was length %d", encbuf, val);
+
+	memset(rawbuf, 0, rawlen + 16);
+
+	enclen = val;
+	val = b32->decode(rawbuf, &rawlen, encbuf, enclen);
+
+	fail_unless(rawlen == 5, "raw length was %d not 5", rawlen);
+	fail_unless(val == 5, "val was not 5 but %d", val);
+	for (i = 0; i < rawlen; i++) {
+		fail_unless(rawbuf[i] == 'A');
+	}
+}
+END_TEST
+
 TCase *
 test_base32_create_tests()
 {
@@ -94,6 +136,7 @@ test_base32_create_tests()
 	tcase_add_loop_test(tc, test_base32_encode, 0, TUPLES);
 	tcase_add_loop_test(tc, test_base32_decode, 0, TUPLES);
 	tcase_add_test(tc, test_base32_5to8_8to5);
+	tcase_add_test(tc, test_base32_blksize);
 
 	return tc;
 }