diff --git a/externals/simplecpp/simplecpp.cpp b/externals/simplecpp/simplecpp.cpp
index 47a0b631a..f94710b35 100644
--- a/externals/simplecpp/simplecpp.cpp
+++ b/externals/simplecpp/simplecpp.cpp
@@ -45,6 +45,11 @@ static bool isHex(const std::string &s)
     return s.size()>2 && (s.compare(0,2,"0x")==0 || s.compare(0,2,"0X")==0);
 }
 
+static bool isOct(const std::string &s)
+{
+    return s.size()>1 && (s[0]=='0') && (s[1] >= '0') && (s[1] < '8');
+}
+
 
 static const simplecpp::TokenString DEFINE("define");
 static const simplecpp::TokenString UNDEF("undef");
@@ -76,9 +81,12 @@ static long long stringToLL(const std::string &s)
 {
     long long ret;
     const bool hex = isHex(s);
-    std::istringstream istr(hex ? s.substr(2) : s);
+    const bool oct = isOct(s);
+    std::istringstream istr(hex ? s.substr(2) : oct ? s.substr(1) : s);
     if (hex)
         istr >> std::hex;
+    else if (oct)
+        istr >> std::oct;
     istr >> ret;
     return ret;
 }
@@ -87,9 +95,12 @@ static unsigned long long stringToULL(const std::string &s)
 {
     unsigned long long ret;
     const bool hex = isHex(s);
-    std::istringstream istr(hex ? s.substr(2) : s);
+    const bool oct = isOct(s);
+    std::istringstream istr(hex ? s.substr(2) : oct ? s.substr(1) : s);
     if (hex)
         istr >> std::hex;
+    else if (oct)
+        istr >> std::oct;
     istr >> ret;
     return ret;
 }
@@ -769,7 +780,7 @@ void simplecpp::TokenList::combineOperators()
         }
         // match: [0-9.]+E [+-] [0-9]+
         const char lastChar = tok->str()[tok->str().size() - 1];
-        if (tok->number && !isHex(tok->str()) && (lastChar == 'E' || lastChar == 'e') && tok->next && tok->next->isOneOf("+-") && tok->next->next && tok->next->next->number) {
+        if (tok->number && !isHex(tok->str()) && !isOct(tok->str()) && (lastChar == 'E' || lastChar == 'e') && tok->next && tok->next->isOneOf("+-") && tok->next->next && tok->next->next->number) {
             tok->setstr(tok->str() + tok->next->op + tok->next->next->str());
             deleteToken(tok->next);
             deleteToken(tok->next);
@@ -830,7 +841,7 @@ void simplecpp::TokenList::combineOperators()
         } else if ((tok->op == '<' || tok->op == '>') && tok->op == tok->next->op) {
             tok->setstr(tok->str() + tok->next->str());
             deleteToken(tok->next);
-            if (tok->next && tok->next->op == '=') {
+            if (tok->next && tok->next->op == '=' && tok->next->next && tok->next->next->op != '=') {
                 tok->setstr(tok->str() + tok->next->str());
                 deleteToken(tok->next);
             }