diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 12839009e3..550021de69 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -420,12 +420,12 @@ reswitch:
 				goto error;
 			}
 			t->bound = mpgetfix(v.u.xval);
-			if(t->bound < 0) {
-				yyerror("array bound must be non-negative");
-				goto error;
-			} else if(doesoverflow(v, types[TINT])) {
+			if(doesoverflow(v, types[TINT])) {
 				yyerror("array bound is too large"); 
 				goto error;
+			} else if(t->bound < 0) {
+				yyerror("array bound must be non-negative");
+				goto error;
 			}
 		}
 		typecheck(&r, Etype);
diff --git a/test/fixedbugs/issue5609.go b/test/fixedbugs/issue5609.go
new file mode 100644
index 0000000000..34619b3418
--- /dev/null
+++ b/test/fixedbugs/issue5609.go
@@ -0,0 +1,13 @@
+// errorcheck
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// issue 5609: overflow when calculating array size
+
+package pkg
+
+const Large uint64 = 18446744073709551615
+
+var foo [Large]uint64 // ERROR "array bound is too large"