diff --git a/linux/mu b/linux/mu
index 75d696b2..c5823b80 100755
Binary files a/linux/mu and b/linux/mu differ
diff --git a/linux/mu.subx b/linux/mu.subx
index 7c6f46c3..ecdb7b43 100644
--- a/linux/mu.subx
+++ b/linux/mu.subx
@@ -31251,6 +31251,47 @@ _Primitive-or-lit-with-mem:  # (payload primitive)
     0/imm32/no-xm32
     0/imm32/no-x32
     0x11/imm32/alloc-id:fake
+    _Primitive-not-reg/imm32/next
+# - not
+_Primitive-not-reg:  # (payload primitive)
+    0x11/imm32/alloc-id:fake:payload
+    # var1/reg <- not => f7 2/subop/not var1/rm32
+    0x11/imm32/alloc-id:fake
+    _string-not/imm32/name
+    0/imm32/no-inouts
+    0/imm32/no-inouts
+    0x11/imm32/alloc-id:fake
+    Single-int-var-in-some-register/imm32/outputs
+    0x11/imm32/alloc-id:fake
+    _string_f7_subop_not/imm32/subx-name
+    3/imm32/rm32-is-first-output
+    0/imm32/no-r32
+    0/imm32/no-imm32
+    0/imm32/no-imm8
+    0/imm32/no-disp32
+    0/imm32/no-xm32
+    0/imm32/no-x32
+    0x11/imm32/alloc-id:fake
+    _Primitive-not-mem/imm32/next
+_Primitive-not-mem:  # (payload primitive)
+    0x11/imm32/alloc-id:fake:payload
+    # not var1 => f7 2/subop/not var1/rm32
+    0x11/imm32/alloc-id:fake
+    _string-not/imm32/name
+    0x11/imm32/alloc-id:fake
+    Single-int-var-in-mem/imm32/inouts
+    0/imm32/no-outputs
+    0/imm32/no-outputs
+    0x11/imm32/alloc-id:fake
+    _string_f7_subop_not/imm32/subx-name
+    1/imm32/rm32-is-first-inout
+    0/imm32/no-r32
+    0/imm32/no-imm32
+    0/imm32/no-imm8
+    0/imm32/no-disp32
+    0/imm32/no-xm32
+    0/imm32/no-x32
+    0x11/imm32/alloc-id:fake
     _Primitive-xor-with-eax/imm32/next
 # - xor
 _Primitive-xor-with-eax:  # (payload primitive)
@@ -34256,6 +34297,11 @@ _string-negate:  # (payload array byte)
     # "negate"
     0x6/imm32/size
     0x6e/n 0x65/e 0x67/g 0x61/a 0x74/t 0x65/e
+_string-not:  # (payload array byte)
+    0x11/imm32/alloc-id:fake:payload
+    # "not"
+    0x3/imm32/size
+    0x6e/n 0x6f/o 0x74/t
 _string-or:  # (payload array byte)
     0x11/imm32/alloc-id:fake:payload
     # "or"
@@ -34823,6 +34869,11 @@ _string_f7_subop_negate:
     # "f7 3/subop/negate"
     0x11/imm32/size
     0x66/f 0x37/7 0x20/space 0x33/3 0x2f/slash 0x73/s 0x75/u 0x62/b 0x6f/o 0x70/p 0x2f/slash 0x6e/n 0x65/e 0x67/g 0x61/a 0x74/t 0x65/e
+_string_f7_subop_not:
+    0x11/imm32/alloc-id:fake:payload
+    # "f7 2/subop/not"
+    0xe/imm32/size
+    0x66/f 0x37/7 0x20/space 0x32/2 0x2f/slash 0x73/s 0x75/u 0x62/b 0x6f/o 0x70/p 0x2f/slash 0x6e/n 0x6f/o 0x74/t
 _string_ff_subop_increment:  # (payload array byte)
     0x11/imm32/alloc-id:fake:payload
     # "ff 0/subop/increment"
diff --git a/mu.md b/mu.md
index dc6d9ff0..e3ed5418 100644
--- a/mu.md
+++ b/mu.md
@@ -221,6 +221,9 @@ or-with var1, var2/reg
 var/reg <- or n
 or-with var, n
 
+var1/reg1 <- not
+not var
+
 var1/reg1 <- xor var2/reg2
 var/reg <- xor var2
 xor-with var1, var2/reg
diff --git a/mu_instructions b/mu_instructions
index 7a458660..2dca40c4 100644
--- a/mu_instructions
+++ b/mu_instructions
@@ -75,6 +75,10 @@ var/reg <- or n                   => "81 1/subop/or %" reg " " n "/imm32"
 or-with var, n                    => "81 1/subop/or *(ebp+" var.stack-offset ") " n "/imm32"
 or-with *var/reg, n               => "81 1/subop/or *" reg " " n "/imm32"
 
+var/reg <- not                    => "f7 2/subop/not %" reg
+not var                           => "f7 2/subop/not *(ebp+" var.stack-offset ")"
+not *var/reg                      => "f7 2/subop/not *" reg
+
 var/reg <- xor var2/reg2          => "31/xor-with %" reg " " reg2 "/r32"
 var/reg <- xor var2               => "33/xor *(ebp+" var2.stack-offset ") " reg "/r32"
 var/reg <- xor *var2/reg2         => "33/xor *" reg2 " " reg "/r32"