diff --git a/packages/minimongo/NOTES b/packages/minimongo/NOTES.md
similarity index 100%
rename from packages/minimongo/NOTES
rename to packages/minimongo/NOTES.md
diff --git a/packages/minimongo/local_collection.js b/packages/minimongo/local_collection.js
index 38b4d5c3a6..e3668eeb03 100644
--- a/packages/minimongo/local_collection.js
+++ b/packages/minimongo/local_collection.js
@@ -1468,6 +1468,24 @@ const MODIFIERS = {
 
     target[field] = new Date();
   },
+  $inc(target, field, arg) {
+    if (typeof arg !== 'number') {
+      throw MinimongoError('Modifier $inc allowed for numbers only', {field});
+    }
+
+    if (field in target) {
+      if (typeof target[field] !== 'number') {
+        throw MinimongoError(
+          'Cannot apply $inc modifier to non-number',
+          {field}
+        );
+      }
+
+      target[field] += arg;
+    } else {
+      target[field] = arg;
+    }
+  },
   $min(target, field, arg) {
     if (typeof arg !== 'number') {
       throw MinimongoError('Modifier $min allowed for numbers only', {field});
@@ -1508,24 +1526,64 @@ const MODIFIERS = {
       target[field] = arg;
     }
   },
-  $inc(target, field, arg) {
+  $mul(target, field, arg) {
     if (typeof arg !== 'number') {
-      throw MinimongoError('Modifier $inc allowed for numbers only', {field});
+      throw MinimongoError('Modifier $mul allowed for numbers only', {field});
     }
 
     if (field in target) {
       if (typeof target[field] !== 'number') {
         throw MinimongoError(
-          'Cannot apply $inc modifier to non-number',
+          'Cannot apply $mul modifier to non-number',
           {field}
         );
       }
 
-      target[field] += arg;
+      target[field] *= arg;
     } else {
-      target[field] = arg;
+      target[field] = 0;
     }
   },
+  $rename(target, field, arg, keypath, doc) {
+    // no idea why mongo has this restriction..
+    if (keypath === arg) {
+      throw MinimongoError('$rename source must differ from target', {field});
+    }
+
+    if (target === null) {
+      throw MinimongoError('$rename source field invalid', {field});
+    }
+
+    if (typeof arg !== 'string') {
+      throw MinimongoError('$rename target must be a string', {field});
+    }
+
+    if (arg.includes('\0')) {
+      // Null bytes are not allowed in Mongo field names
+      // https://docs.mongodb.com/manual/reference/limits/#Restrictions-on-Field-Names
+      throw MinimongoError(
+        'The \'to\' field for $rename cannot contain an embedded null byte',
+        {field}
+      );
+    }
+
+    if (target === undefined) {
+      return;
+    }
+
+    const object = target[field];
+
+    delete target[field];
+
+    const keyparts = arg.split('.');
+    const target2 = findModTarget(doc, keyparts, {forbidArray: true});
+
+    if (target2 === null) {
+      throw MinimongoError('$rename target field invalid', {field});
+    }
+
+    target2[keyparts.pop()] = object;
+  },
   $set(target, field, arg) {
     if (target !== Object(target)) { // not an array or an object
       const error = MinimongoError(
@@ -1810,46 +1868,6 @@ const MODIFIERS = {
       !arg.some(element => LocalCollection._f._equal(object, element))
     );
   },
-  $rename(target, field, arg, keypath, doc) {
-    // no idea why mongo has this restriction..
-    if (keypath === arg) {
-      throw MinimongoError('$rename source must differ from target', {field});
-    }
-
-    if (target === null) {
-      throw MinimongoError('$rename source field invalid', {field});
-    }
-
-    if (typeof arg !== 'string') {
-      throw MinimongoError('$rename target must be a string', {field});
-    }
-
-    if (arg.includes('\0')) {
-      // Null bytes are not allowed in Mongo field names
-      // https://docs.mongodb.com/manual/reference/limits/#Restrictions-on-Field-Names
-      throw MinimongoError(
-        'The \'to\' field for $rename cannot contain an embedded null byte',
-        {field}
-      );
-    }
-
-    if (target === undefined) {
-      return;
-    }
-
-    const object = target[field];
-
-    delete target[field];
-
-    const keyparts = arg.split('.');
-    const target2 = findModTarget(doc, keyparts, {forbidArray: true});
-
-    if (target2 === null) {
-      throw MinimongoError('$rename target field invalid', {field});
-    }
-
-    target2[keyparts.pop()] = object;
-  },
   $bit(target, field, arg) {
     // XXX mongo only supports $bit on integers, and we only support
     // native javascript numbers (doubles) so far, so we can't support $bit
diff --git a/packages/minimongo/minimongo_tests_client.js b/packages/minimongo/minimongo_tests_client.js
index 658f8e12db..95526acaea 100644
--- a/packages/minimongo/minimongo_tests_client.js
+++ b/packages/minimongo/minimongo_tests_client.js
@@ -2659,6 +2659,27 @@ Tinytest.add('minimongo - modify', test => {
   modify({a: {b: 2}}, {$min: {'a.c': 10}}, {a: {b: 2, c: 10}});
   exception({}, {$min: {_id: 1}});
 
+  //$mul
+  modify({a: 1, b: 1}, {$mul: {b: 2}}, {a: 1, b: 2});
+  modify({a: 1, b: 1}, {$mul: {c: 2}}, {a: 1, b: 1, c: 0});
+  modify({a: 1, b: 2}, {$mul: {b: 2}}, {a: 1, b: 4});
+  modify({a: 1, b: 2}, {$mul: {b: 10}}, {a: 1, b: 20});
+  exception({a: 1}, {$mul: {a: '10'}});
+  exception({a: 1}, {$mul: {a: true}});
+  exception({a: 1}, {$mul: {a: [10]}});
+  exception({a: '1'}, {$mul: {a: 10}});
+  exception({a: [1]}, {$mul: {a: 10}});
+  exception({a: {}}, {$mul: {a: 10}});
+  exception({a: false}, {$mul: {a: 10}});
+  exception({a: null}, {$mul: {a: 10}});
+  exception({}, {$mul: {_id: 1}});
+  modify({a: [1, 2]}, {$mul: {'a.1': 2}}, {a: [2, 1]});
+  modify({a: [1, 2]}, {$mul: {'a.1': 3}}, {a: [3, 2]});
+  modify({a: [1, 2]}, {$mul: {'a.2': 10}}, {a: [1, 20]});
+  modify({a: [1, 2]}, {$mul: {'a.3': 10}}, {a: [1, 2, 0]});
+  modify({a: {b: 2}}, {$mul: {'a.b': 1}}, {a: {b: 2}});
+  modify({a: {b: 2}}, {$mul: {'a.c': 10}}, {a: {b: 2, c: 0}});
+
   // $max
   modify({a: 1, b: 2}, {$max: {b: 1}}, {a: 1, b: 2});
   modify({a: 1, b: 2}, {$max: {b: 3}}, {a: 1, b: 3});
diff --git a/packages/minimongo/minimongo_tests_server.js b/packages/minimongo/minimongo_tests_server.js
index eccb8a980a..596eff0781 100644
--- a/packages/minimongo/minimongo_tests_server.js
+++ b/packages/minimongo/minimongo_tests_server.js
@@ -35,8 +35,8 @@ Tinytest.add('minimongo - modifier affects selector', test => {
   // When top-level value is an object, it is treated as a literal,
   // so when you query col.find({ a: { foo: 1, bar: 2 } })
   // it doesn't mean you are looking for anything that has 'a.foo' to be 1 and
-  // 'a.bar' to be 2, instead you are looking for 'a' to be exatly that object
-  // with exatly that order of keys. { a: { foo: 1, bar: 2, baz: 3 } } wouldn't
+  // 'a.bar' to be 2, instead you are looking for 'a' to be exactly that object
+  // with exactly that order of keys. { a: { foo: 1, bar: 2, baz: 3 } } wouldn't
   // match it. That's why in this selector 'a' would be important key, not a.foo
   // and a.bar.
   testSelectorPaths({