diff --git a/src/runtime/string.go b/src/runtime/string.go
index 9a601f0094..d6030a1dca 100644
--- a/src/runtime/string.go
+++ b/src/runtime/string.go
@@ -55,20 +55,20 @@ func concatstrings(buf *tmpBuf, a []string) string {
 	return s
 }
 
-func concatstring2(buf *tmpBuf, a [2]string) string {
-	return concatstrings(buf, a[:])
+func concatstring2(buf *tmpBuf, a0, a1 string) string {
+	return concatstrings(buf, []string{a0, a1})
 }
 
-func concatstring3(buf *tmpBuf, a [3]string) string {
-	return concatstrings(buf, a[:])
+func concatstring3(buf *tmpBuf, a0, a1, a2 string) string {
+	return concatstrings(buf, []string{a0, a1, a2})
 }
 
-func concatstring4(buf *tmpBuf, a [4]string) string {
-	return concatstrings(buf, a[:])
+func concatstring4(buf *tmpBuf, a0, a1, a2, a3 string) string {
+	return concatstrings(buf, []string{a0, a1, a2, a3})
 }
 
-func concatstring5(buf *tmpBuf, a [5]string) string {
-	return concatstrings(buf, a[:])
+func concatstring5(buf *tmpBuf, a0, a1, a2, a3, a4 string) string {
+	return concatstrings(buf, []string{a0, a1, a2, a3, a4})
 }
 
 // slicebytetostring converts a byte slice to a string.