diff --git a/Modules/main.c b/Modules/main.c
index 0fd59c9..27b8493 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -45,7 +45,7 @@
 static int  orig_argc;
 
 /* command line options */
-#define BASE_OPTS L"bBc:dEhiJm:OStuvVW:xX?"
+#define BASE_OPTS L"bBc:dEhiJm:OsStuvVW:xX?"
 
 #define PROGRAM_OPTS BASE_OPTS
 
@@ -70,6 +70,7 @@
 -m mod : run library module as a script (terminates option list)\n\
 -O     : optimize generated bytecode slightly; also PYTHONOPTIMIZE=x\n\
 -OO    : remove doc-strings in addition to the -O optimizations\n\
+-s     : don't add user site directory to sys.path; also PYTHONNOUSERSITE\n\
 -S     : don't imply 'import site' on initialization\n\
 -t     : issue warnings about inconsistent tab usage (-tt: issue errors)\n\
 ";
@@ -355,6 +356,10 @@
 			Py_DontWriteBytecodeFlag++;
 			break;
 
+		case 's':
+			Py_NoUserSiteDirectory++;
+			break;
+
 		case 'S':
 			Py_NoSiteFlag++;
 			break;
@@ -419,6 +424,10 @@
 	    (p = Py_GETENV("PYTHONUNBUFFERED")) && *p != '\0')
 		unbuffered = 1;
 
+	if (!Py_NoUserSiteDirectory &&
+	    (p = Py_GETENV("PYTHONNOUSERSITE")) && *p != '\0')
+		Py_NoUserSiteDirectory = 1;
+
 	if (command == NULL && module == NULL && _PyOS_optind < argc &&
 	    wcscmp(argv[_PyOS_optind], L"-") != 0)
 	{