diff --git a/src/univalue/include/univalue.h b/src/univalue/include/univalue.h
index 908339ad4..73b9464e1 100644
--- a/src/univalue/include/univalue.h
+++ b/src/univalue/include/univalue.h
@@ -25,9 +25,11 @@ public:
         typ = initialType;
         val = initialStr;
     }
+#ifdef __APPLE__
     UniValue(size_t val_) {
         setInt(val_);
     }
+#endif
     UniValue(uint64_t val_) {
         setInt(val_);
     }
@@ -57,7 +59,9 @@ public:
     bool setNull();
     bool setBool(bool val);
     bool setNumStr(const std::string& val);
+#ifdef __APPLE__
     bool setInt(size_t val_);
+#endif
     bool setInt(uint64_t val);
     bool setInt(int64_t val);
     bool setInt(int val_) { return setInt((int64_t)val_); }
@@ -96,10 +100,12 @@ public:
         std::string s(val_);
         return push_back(s);
     }
+#ifdef __APPLE__
     bool push_back(size_t val_) {
         UniValue tmpVal(val_);
         return push_back(tmpVal);
     }
+#endif
     bool push_back(uint64_t val_) {
         UniValue tmpVal(val_);
         return push_back(tmpVal);
@@ -198,12 +204,14 @@ static inline std::pair<std::string,UniValue> Pair(const char *cKey, std::string
     return std::make_pair(key, uVal);
 }
 
+#ifdef __APPLE__
 static inline std::pair<std::string,UniValue> Pair(const char *cKey, size_t sizeVal)
 {
     std::string key(cKey);
     UniValue uVal(sizeVal);
     return std::make_pair(key, uVal);
 }
+#endif
 
 static inline std::pair<std::string,UniValue> Pair(const char *cKey, uint64_t u64Val)
 {
diff --git a/src/univalue/lib/univalue.cpp b/src/univalue/lib/univalue.cpp
index b6c205f16..c1708016d 100644
--- a/src/univalue/lib/univalue.cpp
+++ b/src/univalue/lib/univalue.cpp
@@ -119,6 +119,7 @@ bool UniValue::setNumStr(const string& val_)
     return true;
 }
 
+#ifdef __APPLE__
 bool UniValue::setInt(size_t val_)
 {
     ostringstream oss;
@@ -127,6 +128,7 @@ bool UniValue::setInt(size_t val_)
 
     return setNumStr(oss.str());
 }
+#endif
 
 bool UniValue::setInt(uint64_t val_)
 {