diff --git a/v2/build-system.jam b/v2/build-system.jam
index a555b610d..80258ef19 100644
--- a/v2/build-system.jam
+++ b/v2/build-system.jam
@@ -543,14 +543,15 @@ local rule should-clean-project ( project )
 #
 ################################################################################
 
-{
+{    
     if --version in $(.argv)
     {
         version.print ;
         EXIT ;
     }
-
-
+    
+    version.verify-engine-version ;    
+    
     load-configuration-files ;
 
     local extra-properties ;
diff --git a/v2/build/version.jam b/v2/build/version.jam
index 1d64026d9..7626ddda8 100644
--- a/v2/build/version.jam
+++ b/v2/build/version.jam
@@ -6,26 +6,44 @@
 import errors ;
 import numbers ;
 
+major = "2011" ;
+minor = "04" ;
 
 rule boost-build ( )
 {
-    return "V2 (Milestone 12)" ;
+    return "$(major).$(minor)-svn" ;
 }
 
-
-rule jam ( )
-{
-    local v = [ modules.peek : JAM_VERSION ] ;
-    return $(v:J=.) ;
-}
-
-
 rule print ( )
 {
-    ECHO "Boost.Build" [ boost-build ] ;
-    ECHO "Boost.Jam" [ jam ] ;
+    if [ verify-engine-version ]
+    {        
+        ECHO "Boost.Build" [ boost-build ] ;
+    }    
 }
 
+rule verify-engine-version ( )
+{
+    local v = [ modules.peek : JAM_VERSION ] ;
+    
+    if $(v[1]) != $(major) || $(v[2]) != $(minor)
+    {
+        local argv = [ modules.peek : ARGV ] ;
+        local e = $(argv[1]) ;
+        local l = [ modules.binding version ] ;
+        l = $(l:D) ;
+        l = $(l:D) ;
+        ECHO "warning: mismatched versions of Boost.Build engine and core" ;
+        ECHO "warning: Boost.Build engine ($(e)) is $(v:J=.)" ;
+        ECHO "warning: Boost.Build core (at $(l)) is" [ boost-build ] ;
+    }
+    else
+    {
+        return true ;
+    }    
+}
+
+
 
 # Utility rule for testing whether all elements in a sequence are equal to 0.
 #
diff --git a/v2/engine/patchlevel.h b/v2/engine/patchlevel.h
index 5d5979057..699efd84b 100644
--- a/v2/engine/patchlevel.h
+++ b/v2/engine/patchlevel.h
@@ -7,11 +7,11 @@
 /* Keep JAMVERSYM in sync with VERSION. */
 /* It can be accessed as $(JAMVERSION) in the Jamfile. */
 
-#define VERSION_MAJOR 3
-#define VERSION_MINOR 1
-#define VERSION_PATCH 19
-#define VERSION_MAJOR_SYM "03"
-#define VERSION_MINOR_SYM "1"
-#define VERSION_PATCH_SYM "19"
-#define VERSION "3.1.19"
-#define JAMVERSYM "JAMVERSION=3.1"
+#define VERSION_MAJOR 2011
+#define VERSION_MINOR 04
+#define VERSION_PATCH 0
+#define VERSION_MAJOR_SYM "2011"
+#define VERSION_MINOR_SYM "04"
+#define VERSION_PATCH_SYM "00"
+#define VERSION "2011.4"
+#define JAMVERSYM "JAMVERSION=2011.4"