diff --git a/libraries/stdlib/test/numbers/NumbersTest.kt b/libraries/stdlib/test/numbers/NumbersTest.kt
index aa093e3c3fe..02e4663d648 100644
--- a/libraries/stdlib/test/numbers/NumbersTest.kt
+++ b/libraries/stdlib/test/numbers/NumbersTest.kt
@@ -173,5 +173,23 @@ class NumbersTest {
         }
     }
 
+    @Test fun sizeInBitsAndBytes() {
+        fun testSizes(companion: Any, sizeBytes: Int, sizeBits: Int, expectedSizeBytes: Int) {
+            assertEquals(expectedSizeBytes, sizeBytes, companion.toString())
+            assertEquals(expectedSizeBytes * 8, sizeBits, companion.toString())
+        }
+
+        testSizes(Char, Char.SIZE_BYTES, Char.SIZE_BITS, 2)
+
+        testSizes(Byte, Byte.SIZE_BYTES, Byte.SIZE_BITS, 1)
+        testSizes(Short, Short.SIZE_BYTES, Short.SIZE_BITS, 2)
+        testSizes(Int, Int.SIZE_BYTES, Int.SIZE_BITS, 4)
+        testSizes(Long, Long.SIZE_BYTES, Long.SIZE_BITS, 8)
+
+        testSizes(UByte, UByte.SIZE_BYTES, UByte.SIZE_BITS, 1)
+        testSizes(UShort, UShort.SIZE_BYTES, UShort.SIZE_BITS, 2)
+        testSizes(UInt, UInt.SIZE_BYTES, UInt.SIZE_BITS, 4)
+        testSizes(ULong, ULong.SIZE_BYTES, ULong.SIZE_BITS, 8)
+   }
 
 }
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