4 files changed, 12 insertions, 3 deletions
diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index 76d510efebfc..d6f299d6bfda 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -58,12 +58,12 @@ static void setLogType(string lt)
 }
 
 
-unsigned int getIntArg(const string & opt,
+unsigned long long getIntArg(const string & opt,
     Strings::iterator & i, const Strings::iterator & end)
 {
     ++i;
     if (i == end) throw UsageError(format("`%1%' requires an argument") % opt);
-    int n;
+    long long n;
     if (!string2Int(*i, n) || n < 0)
         throw UsageError(format("`%1%' requires a non-negative integer") % opt);
     return n;
diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index c38eeaf48131..95d80bacdae1 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -26,7 +26,7 @@ namespace nix {
 Path makeRootName(const Path & gcRoot, int & counter);
 void printGCWarning();
 
-unsigned int getIntArg(const string & opt,
+unsigned long long getIntArg(const string & opt,
     Strings::iterator & i, const Strings::iterator & end);
 
 /* Whether we're running setuid. */
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 1873ccfe536c..4f6c367da8b1 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -1020,6 +1020,14 @@ bool string2Int(const string & s, int & n)
 }
 
 
+bool string2Int(const string & s, long long & n)
+{
+    std::istringstream str(s);
+    str >> n;
+    return str && str.get() == EOF;
+}
+
+
 void ignoreException()
 {
     try {
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index d1e30fa6b9e3..5d28a8308cb8 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -287,6 +287,7 @@ bool statusOk(int status);
 /* Parse a string into an integer. */
 string int2String(int n);
 bool string2Int(const string & s, int & n);
+bool string2Int(const string & s, long long & n);
 
 
 /* Exception handling in destructors: print an error message, then