diff --git a/src/util.cpp b/src/util.cpp
index 0a5a899997..e3697183da 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -102,6 +102,7 @@ using namespace std;
 const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf";
 const char * const BITCOIN_PID_FILENAME = "bitcoind.pid";
 
+CCriticalSection cs_args;
 map<string, string> mapArgs;
 static map<string, vector<string> > _mapMultiArgs;
 const map<string, vector<string> >& mapMultiArgs = _mapMultiArgs;
@@ -346,6 +347,7 @@ static void InterpretNegativeSetting(std::string& strKey, std::string& strValue)
 
 void ParseParameters(int argc, const char* const argv[])
 {
+    LOCK(cs_args);
     mapArgs.clear();
     _mapMultiArgs.clear();
 
@@ -381,11 +383,13 @@ void ParseParameters(int argc, const char* const argv[])
 
 bool IsArgSet(const std::string& strArg)
 {
+    LOCK(cs_args);
     return mapArgs.count(strArg);
 }
 
 std::string GetArg(const std::string& strArg, const std::string& strDefault)
 {
+    LOCK(cs_args);
     if (mapArgs.count(strArg))
         return mapArgs[strArg];
     return strDefault;
@@ -393,6 +397,7 @@ std::string GetArg(const std::string& strArg, const std::string& strDefault)
 
 int64_t GetArg(const std::string& strArg, int64_t nDefault)
 {
+    LOCK(cs_args);
     if (mapArgs.count(strArg))
         return atoi64(mapArgs[strArg]);
     return nDefault;
@@ -400,6 +405,7 @@ int64_t GetArg(const std::string& strArg, int64_t nDefault)
 
 bool GetBoolArg(const std::string& strArg, bool fDefault)
 {
+    LOCK(cs_args);
     if (mapArgs.count(strArg))
         return InterpretBool(mapArgs[strArg]);
     return fDefault;
@@ -407,6 +413,7 @@ bool GetBoolArg(const std::string& strArg, bool fDefault)
 
 bool SoftSetArg(const std::string& strArg, const std::string& strValue)
 {
+    LOCK(cs_args);
     if (mapArgs.count(strArg))
         return false;
     mapArgs[strArg] = strValue;
@@ -522,6 +529,8 @@ const boost::filesystem::path &GetDataDir(bool fNetSpecific)
 
 void ClearDatadirCache()
 {
+    LOCK(csPathCached);
+
     pathCached = boost::filesystem::path();
     pathCachedNetSpecific = boost::filesystem::path();
 }
@@ -541,18 +550,21 @@ void ReadConfigFile(const std::string& confPath)
     if (!streamConfig.good())
         return; // No bitcoin.conf file is OK
 
-    set<string> setOptions;
-    setOptions.insert("*");
-
-    for (boost::program_options::detail::config_file_iterator it(streamConfig, setOptions), end; it != end; ++it)
     {
-        // Don't overwrite existing settings so command line settings override bitcoin.conf
-        string strKey = string("-") + it->string_key;
-        string strValue = it->value[0];
-        InterpretNegativeSetting(strKey, strValue);
-        if (mapArgs.count(strKey) == 0)
-            mapArgs[strKey] = strValue;
-        _mapMultiArgs[strKey].push_back(strValue);
+        LOCK(cs_args);
+        set<string> setOptions;
+        setOptions.insert("*");
+
+        for (boost::program_options::detail::config_file_iterator it(streamConfig, setOptions), end; it != end; ++it)
+        {
+            // Don't overwrite existing settings so command line settings override bitcoin.conf
+            string strKey = string("-") + it->string_key;
+            string strValue = it->value[0];
+            InterpretNegativeSetting(strKey, strValue);
+            if (mapArgs.count(strKey) == 0)
+                mapArgs[strKey] = strValue;
+            _mapMultiArgs[strKey].push_back(strValue);
+        }
     }
     // If datadir is changed in .conf file:
     ClearDatadirCache();