diff --git a/NEWS.rst b/NEWS.rst
index d56dce5..476177c 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -11,6 +11,11 @@ Removals
 * Literal keywords are no longer parsed differently in calls to functions
   with certain names.
 
+New Features
+------------------------------
+* All augmented assignment operators (except `%=` and `^=`) now allow
+  more than two arguments.
+
 Bug Fixes
 ------------------------------
 * Statements in the second argument of `assert` are now executed.
diff --git a/hy/compiler.py b/hy/compiler.py
index 4387366..6d09afa 100755
--- a/hy/compiler.py
+++ b/hy/compiler.py
@@ -1265,19 +1265,21 @@ class HyASTCompiler(object):
         return ret + asty.Compare(
             expr, left=exprs[0], ops=ops, comparators=exprs[1:])
 
-    m_ops = {"+": ast.Add,
-             "/": ast.Div,
-             "//": ast.FloorDiv,
-             "*": ast.Mult,
-             "-": ast.Sub,
-             "%": ast.Mod,
-             "**": ast.Pow,
-             "<<": ast.LShift,
-             ">>": ast.RShift,
-             "|": ast.BitOr,
-             "^": ast.BitXor,
-             "&": ast.BitAnd,
-             "@": ast.MatMult}
+    # The second element of each tuple below is an aggregation operator
+    # that's used for augmented assignment with three or more arguments.
+    m_ops = {"+": (ast.Add, "+"),
+             "/": (ast.Div, "*"),
+             "//": (ast.FloorDiv, "*"),
+             "*": (ast.Mult, "*"),
+             "-": (ast.Sub, "+"),
+             "%": (ast.Mod, None),
+             "**": (ast.Pow, "**"),
+             "<<": (ast.LShift, "+"),
+             ">>": (ast.RShift, "+"),
+             "|": (ast.BitOr, "|"),
+             "^": (ast.BitXor, None),
+             "&": (ast.BitAnd, "&"),
+             "@": (ast.MatMult, "@")}
 
     @special(["+", "*", "|"], [many(FORM)])
     @special(["-", "/", "&", "@"], [oneplus(FORM)])
@@ -1302,7 +1304,7 @@ class HyASTCompiler(object):
                 # Return the argument unchanged.
                 return self.compile(args[0])
 
-        op = self.m_ops[root]
+        op = self.m_ops[root][0]
         right_associative = root == "**"
         ret = self.compile(args[-1 if right_associative else 0])
         for child in args[-2 if right_associative else 1 ::
@@ -1318,11 +1320,16 @@ class HyASTCompiler(object):
 
     a_ops = {x + "=": v for x, v in m_ops.items()}
 
-    @special(list(a_ops.keys()), [FORM, FORM])
-    def compile_augassign_expression(self, expr, root, target, value):
-        op = self.a_ops[root]
+    @special([x for x, (_, v) in a_ops.items() if v is not None], [FORM, oneplus(FORM)])
+    @special([x for x, (_, v) in a_ops.items() if v is None], [FORM, times(1, 1, FORM)])
+    def compile_augassign_expression(self, expr, root, target, values):
+        if len(values) > 1:
+            return self.compile(mkexpr(root, [target],
+                mkexpr(self.a_ops[root][1], rest=values)).replace(expr))
+
+        op = self.a_ops[root][0]
         target = self._storeize(target, self.compile(target))
-        ret = self.compile(value)
+        ret = self.compile(values[0])
         return ret + asty.AugAssign(
             expr, target=target, value=ret.force_expr, op=op())
 
diff --git a/tests/native_tests/mathematics.hy b/tests/native_tests/mathematics.hy
deleted file mode 100644
index 5069644..0000000
--- a/tests/native_tests/mathematics.hy
+++ /dev/null
@@ -1,199 +0,0 @@
-;; Copyright 2019 the authors.
-;; This file is part of Hy, which is free software licensed under the Expat
-;; license. See the LICENSE.
-
-(setv square (fn [x]
-               (* x x)))
-
-
-(setv test_basic_math (fn []
-                        "NATIVE: Test basic math."
-                        (assert (= (+ 2 2) 4))))
-
-(setv test_mult (fn []
-                  "NATIVE: Test multiplication."
-                  (assert (= 4 (square 2)))
-                  (assert (= 8 (* 8)))
-                  (assert (= 1 (*)))))
-
-
-(setv test_sub (fn []
-                 "NATIVE: Test subtraction"
-                 (assert (= 4 (- 8 4)))
-                 (assert (= -8 (- 8)))))
-
-
-(setv test_add (fn []
-                 "NATIVE: Test addition"
-                 (assert (= 4 (+ 1 1 1 1)))
-                 (assert (= 8 (+ 8)))
-                 (assert (= 0 (+)))))
-
-
-(defn test-add-unary []
-  "NATIVE: test that unary + calls __pos__"
-
-  (defclass X [object]
-    (defn __pos__ [self] "called __pos__"))
-  (assert (= (+ (X)) "called __pos__"))
-
-  ; Make sure the shadowed version works, too.
-  (setv f +)
-  (assert (= (f (X)) "called __pos__")))
-
-
-(setv test_div (fn []
-                 "NATIVE: Test division"
-                 (assert (= 25 (/ 100 2 2)))
-                                ; Commented out until float constants get implemented
-                                ; (assert (= 0.5 (/ 1 2)))
-                 (assert (= 1 (* 2 (/ 1 2))))))
-
-(setv test_int_div (fn []
-                     "NATIVE: Test integer division"
-                     (assert (= 25 (// 101 2 2)))))
-
-(defn test-modulo []
-  "NATIVE: test mod"
-  (assert (= (% 10 2) 0)))
-
-(defn test-pow []
-  "NATIVE: test pow"
-  (assert (= (** 10 2) 100)))
-
-(defn test-lshift []
-  "NATIVE: test lshift"
-  (assert (= (<< 1 2) 4)))
-
-(defn test-rshift []
-  "NATIVE: test lshift"
-  (assert (= (>> 8 1) 4)))
-
-(defn test-bitor []
-  "NATIVE: test lshift"
-  (assert (= (| 1 2) 3)))
-
-(defn test-bitxor []
-  "NATIVE: test xor"
-  (assert (= (^ 1 2) 3)))
-
-(defn test-bitand []
-  "NATIVE: test lshift"
-  (assert (= (& 1 2) 0)))
-
-(defn test-augassign-add []
-  "NATIVE: test augassign add"
-  (setv x 1)
-  (+= x 41)
-  (assert (= x 42)))
-
-(defn test-augassign-sub []
-  "NATIVE: test augassign sub"
-  (setv x 1)
-  (-= x 41)
-  (assert (= x -40)))
-
-(defn test-augassign-mult []
-  "NATIVE: test augassign mult"
-  (setv x 1)
-  (*= x 41)
-  (assert (= x 41)))
-
-(defn test-augassign-div []
-  "NATIVE: test augassign div"
-  (setv x 42)
-  (/= x 2)
-  (assert (= x 21)))
-
-(defn test-augassign-floordiv []
-  "NATIVE: test augassign floordiv"
-  (setv x 42)
-  (//= x 2)
-  (assert (= x 21)))
-
-(defn test-augassign-mod []
-  "NATIVE: test augassign mod"
-  (setv x 42)
-  (%= x 2)
-  (assert (= x 0)))
-
-(defn test-augassign-pow []
-  "NATIVE: test augassign pow"
-  (setv x 2)
-  (**= x 3)
-  (assert (= x 8)))
-
-(defn test-augassign-lshift []
-  "NATIVE: test augassign lshift"
-  (setv x 2)
-  (<<= x 2)
-  (assert (= x 8)))
-
-(defn test-augassign-rshift []
-  "NATIVE: test augassign rshift"
-  (setv x 8)
-  (>>= x 1)
-  (assert (= x 4)))
-
-(defn test-augassign-bitand []
-  "NATIVE: test augassign bitand"
-  (setv x 8)
-  (&= x 1)
-  (assert (= x 0)))
-
-(defn test-augassign-bitor []
-  "NATIVE: test augassign bitand"
-  (setv x 0)
-  (|= x 2)
-  (assert (= x 2)))
-
-(defn test-augassign-bitxor []
-  "NATIVE: test augassign bitand"
-  (setv x 1)
-  (^= x 1)
-  (assert (= x 0)))
-
-(defn overflow-int-to-long []
-  "NATIVE: test if int does not raise an overflow exception"
-  (assert (integer? (+ 1 1000000000000000000000000))))
-
-
-(defclass HyTestMatrix [list]
-  (defn --matmul-- [self other]
-    (setv n (len self)
-          m (len (. other [0]))
-          result [])
-    (for [i (range m)]
-      (setv result-row [])
-      (for [j (range n)]
-        (setv dot-product 0)
-        (for [k (range (len (. self [0])))]
-          (+= dot-product (* (. self [i] [k])
-                             (. other [k] [j]))))
-        (.append result-row dot-product))
-      (.append result result-row))
-    result))
-
-(setv first-test-matrix (HyTestMatrix [[1 2 3]
-                                       [4 5 6]
-                                       [7 8 9]]))
-
-(setv second-test-matrix (HyTestMatrix [[2 0 0]
-                                        [0 2 0]
-                                        [0 0 2]]))
-
-(setv product-of-test-matrices (HyTestMatrix [[ 2  4  6]
-                                              [ 8 10 12]
-                                              [14 16 18]]))
-
-(defn test-matmul []
-  "NATIVE: test matrix multiplication"
-  (assert (= (@ first-test-matrix second-test-matrix)
-             product-of-test-matrices)))
-
-(defn test-augassign-matmul []
-  "NATIVE: test augmented-assignment matrix multiplication"
-  (setv matrix first-test-matrix
-        matmul-attempt (try (@= matrix second-test-matrix)
-                              (except [e [Exception]] e)))
-  (assert (= product-of-test-matrices matrix)))
diff --git a/tests/native_tests/operators.hy b/tests/native_tests/operators.hy
index 7c9b18b..4445138 100644
--- a/tests/native_tests/operators.hy
+++ b/tests/native_tests/operators.hy
@@ -303,3 +303,43 @@
   (assert (= (f "hello" 1) "e"))
   (assert (= (f [[1 2 3] [4 5 6] [7 8 9]] 1 2) 6))
   (assert (= (f {"x" {"y" {"z" 12}}} "x" "y" "z") 12)))
+
+
+(defn test-augassign []
+    (setv b 2  c 3  d 4)
+    (defmacro same-as [expr1 expr2 expected-value]
+      `(do
+        (setv a 4)
+        ~expr1
+        (setv expr1-value a)
+        (setv a 4)
+        ~expr2
+        (assert (= expr1-value a ~expected-value))))
+    (same-as (+= a b c d) (+= a (+ b c d)) 13)
+    (same-as (-= a b c d) (-= a (+ b c d)) -5)
+    (same-as (*= a b c d) (*= a (* b c d)) 96)
+    (same-as (**= a b c) (**= a (** b c)) 65,536)
+    (same-as (/= a b c d) (/= a (* b c d)) (/ 1 6))
+    (same-as (//= a b c d) (//= a (* b c d)) 0)
+    (same-as (<<= a b c d) (<<= a (+ b c d)) 0b10_00000_00000)
+    (same-as (>>= a b c d) (>>= a (+ b c d)) 0)
+    (same-as (&= a b c d) (&= a (& b c d)) 0)
+    (same-as (|= a b c d) (|= a (| b c d)) 0b111)
+
+    (defclass C [object]
+      (defn __init__ [self content] (setv self.content content))
+      (defn __matmul__ [self other] (C (+ self.content other.content))))
+    (setv  a (C "a")  b (C "b")  c (C "c")  d (C "d"))
+    (@= a b c d)
+    (assert (= a.content "abcd"))
+    (setv a (C "a"))
+    (@= a (@ b c d))
+    (assert (= a.content "abcd"))
+
+    (setv a 15)
+    (%= a 9)
+    (assert (= a 6))
+
+    (setv a 0b1100)
+    (^= a 0b1010)
+    (assert (= a 0b0110)))