diff --git a/db/curop.h b/db/curop.h
index c21478c1608..22b3871601d 100644
--- a/db/curop.h
+++ b/db/curop.h
@@ -150,6 +150,8 @@ namespace mongo {
         
         ThreadSafeString _message;
         ProgressMeter _progressMeter;
+        
+        volatile bool _killed;
 
         void _reset(){
             _command = false;
@@ -159,6 +161,7 @@ namespace mongo {
             _waitingForLock = false;
             _message = "";
             _progressMeter.finished();
+            _killed = false;
         }
 
         void setNS(const char *ns) {
@@ -338,53 +341,57 @@ namespace mongo {
         string getMessage() const { return _message.toString(); }
         ProgressMeter& getProgressMeter() { return _progressMeter; }
 
+        void kill() { _killed = true; }
+        bool killed() const { return _killed; }
+
         friend class Client;
     };
 
-    /* 0 = ok
-       1 = kill current operation and reset this to 0
-       future: maybe use this as a "going away" thing on process termination with a higher flag value 
+    /* _globalKill: we are shutting down
+       otherwise kill attribute set on specified CurOp
+       this class does not handle races between interruptJs and the checkForInterrupt functions - those must be
+       handled by the client of this class
     */
     extern class KillCurrentOp { 
-        enum { Off, On, All } state;
-        AtomicUInt toKill;
+        volatile bool _globalKill;
     public:
-        // the kill functions are not called with a mutex
-        void killAll() { state = All; interruptJs( 0 ); }
-        void kill(AtomicUInt i) { toKill = i; state = On; interruptJs( &i ); }
-        
-        // this is called without a mutex also, which means we can miss some
-        // kill requests; it's no worse than what the code was doing before,
-        // though, so I don't feel too bad about adding this function.
-        // hopefully we will have time for SERVER-1816 to fix this
-        void finishOp() {
-            if( state == On && cc().curop()->opNum() == toKill ) { 
-                state = Off;
+        void killAll() {
+            _globalKill = true;
+            interruptJs( 0 );
+        }
+        void kill(AtomicUInt i) {
+            {
+                scoped_lock l( Client::clientsMutex );
+                for( set< Client* >::const_iterator j = Client::clients.begin(); j != Client::clients.end(); ++j ) {
+                    if ( ( *j )->curop()->opNum() == i ) {
+                        ( *j )->curop()->kill();
+                        break;
+                    }
+                }
             }
+            interruptJs( &i );
         }
         
-        void checkForInterrupt() { 
-            if( state != Off ) { 
-                if( state == All ) {
-                    uasserted(11600,"interrupted at shutdown");
-                }
-                if( cc().curop()->opNum() == toKill ) { 
-                    uasserted(11601,"interrupted");
-                }
+        void checkForInterrupt() {
+            if( _globalKill ) {
+                uasserted(11600,"interrupted at shutdown");
+            }
+            if( cc().curop()->killed() ) { 
+                uasserted(11601,"interrupted");
             }
         }
         
         const char *checkForInterruptNoAssert() {
-            if( state != Off ) { 
-                if( state == All ) 
-                    return "interrupted at shutdown";
-                if( cc().curop()->opNum() == toKill ) { 
-                    return "interrupted";
-                }
+            if( _globalKill ) {
+                return "interrupted at shutdown";
+            }
+            if( cc().curop()->killed() ) { 
+                return "interrupted";
             }
             return "";
         }
         
+    private:
         void interruptJs( AtomicUInt *op ) {
             if ( !globalScriptEngine ) {
                 return;
diff --git a/db/instance.cpp b/db/instance.cpp
index fdce160e949..6968b970b20 100644
--- a/db/instance.cpp
+++ b/db/instance.cpp
@@ -340,7 +340,6 @@ namespace mongo {
         }
         currentOp.ensureStarted();
         currentOp.done();
-        killCurrentOp.finishOp();
         int ms = currentOp.totalTimeMillis();
         
         log = log || (logLevel >= 2 && ++ctr % 512 == 0);
diff --git a/jstests/killop.js b/jstests/killop.js
new file mode 100644
index 00000000000..463292e63d2
--- /dev/null
+++ b/jstests/killop.js
@@ -0,0 +1,38 @@
+t = db.jstests_killop
+t.drop();
+
+function debug( x ) {
+    printjson( x );
+}
+
+t.save( {} );
+db.getLastError();
+
+function ops() {
+    p = db.currentOp().inprog;
+    debug( p );
+    ids = [];
+    for ( var i in p ) {
+        var o = p[ i ];
+        if ( o.active && o.query && o.query.query && o.query.query.$where && o.ns == "test.jstests_killop" ) {
+            ids.push( o.opid );
+        }
+    }
+    return ids;
+}
+
+s1 = startParallelShell( "db.jstests_killop.count( { $where: function() { while( 1 ) { ; } } } )" );
+s2 = startParallelShell( "db.jstests_killop.count( { $where: function() { while( 1 ) { ; } } } )" );
+
+o = [];
+assert.soon( function() { o = ops(); return o.length == 2; } );
+db.killOp( o[ 0 ] );
+db.killOp( o[ 1 ] );
+
+start = new Date();
+
+s1();
+s2();
+
+// don't want to pass if timeout killed the js function
+assert( ( new Date() ) - start < 30000 );
diff --git a/mongo.xcodeproj/project.pbxproj b/mongo.xcodeproj/project.pbxproj
index bc152affc56..cf962caafac 100644
--- a/mongo.xcodeproj/project.pbxproj
+++ b/mongo.xcodeproj/project.pbxproj
@@ -70,6 +70,8 @@
 		932D855311AB912B002749FB /* fm4.js */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.javascript; path = fm4.js; sourceTree = "<group>"; };
 		932D855411AB912B002749FB /* geo_box1.js */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.javascript; path = geo_box1.js; sourceTree = "<group>"; };
 		93386F98125A7BB4005E0172 /* evale.js */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.javascript; path = evale.js; sourceTree = "<group>"; };
+		93386FDA125A9357005E0172 /* drop2.js */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.javascript; path = drop2.js; sourceTree = "<group>"; };
+		93386FDB125A9661005E0172 /* killop.js */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.javascript; path = killop.js; sourceTree = "<group>"; };
 		933A4D130F55A68600145C4B /* authTest.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = authTest.cpp; sourceTree = "<group>"; };
 		933A4D150F55A68600145C4B /* clientTest.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = clientTest.cpp; sourceTree = "<group>"; };
 		933A4D170F55A68600145C4B /* first.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = first.cpp; sourceTree = "<group>"; };
@@ -842,6 +844,8 @@
 		934BEB9A10DFFA9600178102 /* jstests */ = {
 			isa = PBXGroup;
 			children = (
+				93386FDB125A9661005E0172 /* killop.js */,
+				93386FDA125A9357005E0172 /* drop2.js */,
 				93386F98125A7BB4005E0172 /* evale.js */,
 				936D5EC71251BA2A0015722C /* rename4.js */,
 				93B771FE124024A4007C8F0C /* evald.js */,