diff --git a/constraints_test.go b/constraints_test.go
index a45714d..9ee287f 100644
--- a/constraints_test.go
+++ b/constraints_test.go
@@ -53,6 +53,12 @@ func TestParseConstraint(t *testing.T) {
 			includeMin: true,
 			includeMax: false,
 		}, false},
+		{"^1.1.0-12-abc123", rangeConstraint{
+			min:        Version{major: 1, minor: 1, patch: 0, pre: "12-abc123"},
+			max:        newV(2, 0, 0),
+			includeMin: true,
+			includeMax: false,
+		}, false},
 	}
 
 	for _, tc := range tests {
@@ -70,7 +76,7 @@ func TestParseConstraint(t *testing.T) {
 		}
 
 		if !constraintEq(tc.c, c) {
-			t.Errorf("Incorrect version found on %s", tc.in)
+			t.Errorf("%q produced constraint %q, but expected %q", tc.in, c, tc.c)
 		}
 	}
 }
diff --git a/parse.go b/parse.go
index d6afa6c..f40537d 100644
--- a/parse.go
+++ b/parse.go
@@ -7,6 +7,9 @@ import (
 )
 
 func rewriteRange(i string) string {
+	if versionRegex.MatchString(i) {
+		return i
+	}
 	m := constraintRangeRegex.FindAllStringSubmatch(i, -1)
 	if m == nil {
 		return i