diff --git a/Jamroot.jam b/Jamroot.jam
index ccc84f2d5..b22b8e9d6 100644
--- a/Jamroot.jam
+++ b/Jamroot.jam
@@ -22,7 +22,9 @@ path-constant SELF : . ;
 
 project b2
     : build-dir .build
-    : requirements <cxxstd>11
+    : requirements
+        <cxxstd>11
+        <toolset>msvc:<define>_CRT_SECURE_NO_WARNINGS=1
     ;
 
 #|
diff --git a/src/engine/jam_strings.cpp b/src/engine/jam_strings.cpp
index 5094c5e2b..c9ed8a17f 100644
--- a/src/engine/jam_strings.cpp
+++ b/src/engine/jam_strings.cpp
@@ -191,8 +191,8 @@ void string_unit_test()
 {
     {
         string s[ 1 ];
-        unsigned int i;
-        int const limit = sizeof( s->opt ) * 2 + 2;
+        unsigned long i;
+        unsigned long const limit = sizeof( s->opt ) * 2 + 2;
         string_new( s );
         assert( s->value == s->opt );
         for ( i = 0; i < limit; ++i )