diff --git a/src/test/uint256_tests.cpp b/src/test/uint256_tests.cpp
--- a/src/test/uint256_tests.cpp
+++ b/src/test/uint256_tests.cpp
@@ -124,24 +124,24 @@
 // <= >= < >
 BOOST_AUTO_TEST_CASE(comparison) {
     uint256 LastL;
-    for (int i = 255; i >= 0; --i) {
+    for (int i = 0; i < 256; i++) {
         uint256 TmpL;
-        *(TmpL.begin() + (i >> 3)) |= 1 << (7 - (i & 7));
+        *(TmpL.begin() + (i >> 3)) |= 1 << (i & 7);
         CheckComparison(LastL, TmpL);
         LastL = TmpL;
     }
 
     CheckComparison(ZeroL, R1L);
-    CheckComparison(R2L, R1L);
+    CheckComparison(R1L, R2L);
     CheckComparison(ZeroL, OneL);
     CheckComparison(OneL, MaxL);
     CheckComparison(R1L, MaxL);
     CheckComparison(R2L, MaxL);
 
     uint160 LastS;
-    for (int i = 159; i >= 0; --i) {
+    for (int i = 0; i < 160; i++) {
         uint160 TmpS;
-        *(TmpS.begin() + (i >> 3)) |= 1 << (7 - (i & 7));
+        *(TmpS.begin() + (i >> 3)) |= 1 << (i & 7);
         CheckComparison(LastS, TmpS);
         LastS = TmpS;
     }
diff --git a/src/uint256.h b/src/uint256.h
--- a/src/uint256.h
+++ b/src/uint256.h
@@ -38,9 +38,18 @@
     void SetNull() { memset(data, 0, sizeof(data)); }
 
     inline int Compare(const base_blob &other) const {
-        // This doesn't quite work as you'd expect because the comparison use
-        // the wrong endianess.
-        return memcmp(data, other.data, sizeof(data));
+        for (size_t i = 0; i < sizeof(data); i++) {
+            uint8_t a = data[sizeof(data) - 1 - i];
+            uint8_t b = other.data[sizeof(data) - 1 - i];
+            if (a > b) {
+                return 1;
+            }
+            if (a < b) {
+                return -1;
+            }
+        }
+
+        return 0;
     }
 
     friend inline bool operator==(const base_blob &a, const base_blob &b) {