diff --git a/include/decaf.hxx b/include/decaf.hxx
index 380d345..5ce71ce 100644
--- a/include/decaf.hxx
+++ b/include/decaf.hxx
@@ -102,7 +102,7 @@ public:
     inline Scalar(const decaf_448_scalar_t &t = decaf_448_scalar_zero) NOEXCEPT {  decaf_448_scalar_copy(s,t); } 
     
     /** @brief Copy constructor. */
-    inline Scalar(const Scalar &x) NOEXCEPT {  decaf_448_scalar_copy(s,x.s); }
+    inline Scalar(const Scalar &x) NOEXCEPT {  *this = x; }
     
     /** @brief Construct from arbitrary-length little-endian byte sequence. */
     inline explicit Scalar(const std::string &str) NOEXCEPT { *this = str; }
@@ -408,6 +408,9 @@ public:
     /** @brief Multiply by s.inverse().  If s=0, maps to the identity. */
     inline Point &operator/=(const Scalar &s)       NOEXCEPT { return (*this) *= s.inverse(); }
     
+    /** @brief Validate / sanity check */
+    inline bool validate() const NOEXCEPT { return !!decaf_448_point_valid(p); }
+    
     /** @brief Double-scalar multiply, equivalent to q*qs + r*rs but faster. */
     static inline Point double_scalarmul (
         const Point &q, const Scalar &qs, const Point &r, const Scalar &rs
diff --git a/test/test_decaf.cxx b/test/test_decaf.cxx
index 8ed6f4d..742e38e 100644
--- a/test/test_decaf.cxx
+++ b/test/test_decaf.cxx
@@ -95,13 +95,15 @@ static bool point_check(
     const Point &r,
     const char *name
 ) {
-    if (l == r) return true;
+    bool good = l==r;
+    if (!p.validate()) { good = false; printf("  p invalid\n"); }
+    if (!q.validate()) { good = false; printf("  q invalid\n"); }
+    if (!r.validate()) { good = false; printf("  r invalid\n"); }
+    if (!l.validate()) { good = false; printf("  l invalid\n"); }
+    if (good) return true;
+    
     test.fail();
     printf("  %s", name);
-    if (!decaf_448_point_valid(p.p)) printf("  p invalid\n");
-    if (!decaf_448_point_valid(q.p)) printf("  q invalid\n");
-    if (!decaf_448_point_valid(r.p)) printf("  r invalid\n");
-    if (!decaf_448_point_valid(l.p)) printf("  l invalid\n");
     print("x", x);
     print("y", y);
     print("p", p);