diff --git a/common.go b/common.go
index dd6b61bd..792158ce 100644
--- a/common.go
+++ b/common.go
@@ -508,10 +508,7 @@ func writeVarBytes(w io.Writer, pver uint32, bytes []byte) error {
 // can be properly tested by passing a fake reader in the tests.
 func randomUint64(r io.Reader) (uint64, error) {
 	var b [8]byte
-	n, err := r.Read(b[:])
-	if n != len(b) {
-		return 0, io.ErrShortBuffer
-	}
+	_, err := io.ReadFull(r, b[:])
 	if err != nil {
 		return 0, err
 	}
diff --git a/common_test.go b/common_test.go
index 21706ee5..fbafe248 100644
--- a/common_test.go
+++ b/common_test.go
@@ -691,24 +691,13 @@ func TestRandomUint64(t *testing.T) {
 // and checks the results accordingly.
 func TestRandomUint64Errors(t *testing.T) {
 	// Test short reads.
-	fr := &fakeRandReader{n: 2, err: nil}
+	fr := &fakeRandReader{n: 2, err: io.EOF}
 	nonce, err := btcwire.TstRandomUint64(fr)
-	if err != io.ErrShortBuffer {
+	if err != io.ErrUnexpectedEOF {
 		t.Errorf("TestRandomUint64Fails: Error not expected value of %v [%v]",
 			io.ErrShortBuffer, err)
 	}
 	if nonce != 0 {
 		t.Errorf("TestRandomUint64Fails: nonce is not 0 [%v]", nonce)
 	}
-
-	// Test err with full read.
-	fr = &fakeRandReader{n: 20, err: io.ErrClosedPipe}
-	nonce, err = btcwire.TstRandomUint64(fr)
-	if err != io.ErrClosedPipe {
-		t.Errorf("TestRandomUint64Fails: Error not expected value of %v [%v]",
-			io.ErrClosedPipe, err)
-	}
-	if nonce != 0 {
-		t.Errorf("TestRandomUint64Fails: nonce is not 0 [%v]", nonce)
-	}
 }