diff --git a/cover/profile.go b/cover/profile.go
index a53bf4ea29..958881a2a2 100644
--- a/cover/profile.go
+++ b/cover/profile.go
@@ -66,7 +66,7 @@ func ParseProfiles(fileName string) ([]*Profile, error) {
 		}
 		m := lineRe.FindStringSubmatch(line)
 		if m == nil {
-			return nil, fmt.Errorf("line %q doesn't match expected format: %v", m, lineRe)
+			return nil, fmt.Errorf("line %q doesn't match expected format: %v", line, lineRe)
 		}
 		fn := m[1]
 		p := files[fn]