diff --git a/vlib/base64/base64_test.v b/vlib/base64/base64_test.v
index 55f3dc80c6..e9a92a7fff 100644
--- a/vlib/base64/base64_test.v
+++ b/vlib/base64/base64_test.v
@@ -1,5 +1,38 @@
 import base64
 
+struct testpair {
+	decoded string
+	encoded string
+}
+
+const (
+	pairs = [
+		// RFC 3548 examples
+		testpair{'\x14\xfb\x9c\x03\xd9\x7e', 'FPucA9l+'},
+		testpair{'\x14\xfb\x9c\x03\xd9', 'FPucA9k='},
+		testpair{'\x14\xfb\x9c\x03', 'FPucAw=='},
+
+		// RFC 4648 examples
+		testpair{'', ''},
+		testpair{'f', 'Zg=='},
+		testpair{'fo', 'Zm8='},
+		testpair{'foo', 'Zm9v'},
+		testpair{'foob', 'Zm9vYg=='},
+		testpair{'fooba', 'Zm9vYmE='},
+		testpair{'foobar', 'Zm9vYmFy'},
+
+		// Wikipedia examples
+		testpair{'sure.', 'c3VyZS4='},
+		testpair{'sure', 'c3VyZQ=='},
+		testpair{'sur', 'c3Vy'},
+		testpair{'su', 'c3U='},
+		testpair{'leasure.', 'bGVhc3VyZS4='},
+		testpair{'easure.', 'ZWFzdXJlLg=='},
+		testpair{'asure.', 'YXN1cmUu'},
+		testpair{'sure.', 'c3VyZS4='},
+	]
+)
+
 fn test_decode() {
 	assert base64.decode('TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGludWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=')
 	== 'Man is distinguished, not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.'
@@ -8,9 +41,25 @@ fn test_decode() {
 	assert base64.decode('aGk') == 'hi'
 	assert base64.decode('aGk=') == 'hi'
 	assert base64.decode('aGk==') == 'hi'
+
+	for i, p in pairs {
+		got := base64.decode(p.encoded)
+		if got != p.decoded {
+			eprintln('pairs[${i}]: expected = ${p.decoded}, got = ${got}')
+			assert false
+		}
+	}
 }
 
 fn test_encode() {
 	assert base64.encode('Man is distinguished, not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.')
 	== 'TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGludWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4='
+
+	for i, p in pairs {
+		got := base64.encode(p.decoded)
+		if got != p.encoded {
+			eprintln('pairs[${i}]: expected = ${p.encoded}, got = ${got}')
+			assert false
+		}
+	}
 }