diff --git a/AST.hs b/AST.hs
index 2a9aeb0..3689fcb 100644
--- a/AST.hs
+++ b/AST.hs
@@ -275,6 +275,7 @@ data ExpressionList =
 -- Nothing to do with Haskell monads.
 data MonadicOp =
   MonadicSubtr
+  | MonadicMinus
   | MonadicBitNot
   | MonadicNot
   deriving (Show, Eq, Typeable, Data)
diff --git a/EvalConstants.hs b/EvalConstants.hs
index 7375d96..0b6e753 100644
--- a/EvalConstants.hs
+++ b/EvalConstants.hs
@@ -185,6 +185,7 @@ evalMonadic :: A.MonadicOp -> OccValue -> EvalM OccValue
 -- This, oddly, is probably the most important rule here: "-4" isn't a literal
 -- in occam, it's an operator applied to a literal.
 evalMonadic A.MonadicSubtr a = evalMonadicOp negate a
+evalMonadic A.MonadicMinus a = evalMonadicOp negate a
 evalMonadic A.MonadicBitNot a = evalMonadicOp complement a
 evalMonadic A.MonadicNot (OccBool b) = return $ OccBool (not b)
 evalMonadic _ _ = throwError "bad monadic op"
diff --git a/GenerateC.hs b/GenerateC.hs
index ab3cdd1..6fccf75 100644
--- a/GenerateC.hs
+++ b/GenerateC.hs
@@ -106,6 +106,7 @@ data GenOps = GenOps {
     genFormal :: GenOps -> A.Formal -> CGen (),
     genFormals :: GenOps -> [A.Formal] -> CGen (),
     genFuncDyadic :: GenOps -> Meta -> String -> A.Expression -> A.Expression -> CGen (),
+    genFuncMonadic :: GenOps -> Meta -> String -> A.Expression -> CGen (),
     genIf :: GenOps -> Meta -> A.Structured -> CGen (),
     genInput :: GenOps -> A.Variable -> A.InputMode -> CGen (),
     genInputCase :: GenOps -> Meta -> A.Variable -> A.Structured -> CGen (),
@@ -191,6 +192,7 @@ cgenOps = GenOps {
     genFormal = cgenFormal,
     genFormals = cgenFormals,
     genFuncDyadic = cgenFuncDyadic,
+    genFuncMonadic = cgenFuncMonadic,
     genIf = cgenIf,
     genInput = cgenInput,
     genInputCase = cgenInputCase,
@@ -826,8 +828,19 @@ cgenSimpleMonadic ops s e
           call genExpression ops e
           tell [")"]
 
+cgenFuncMonadic :: GenOps -> Meta -> String -> A.Expression -> CGen ()
+cgenFuncMonadic ops m s e
+    =  do t <- typeOfExpression e
+          call genTypeSymbol ops s t
+          tell [" ("]
+          call genExpression ops e
+          tell [", "]
+          genMeta m
+          tell [")"]
+
 cgenMonadic :: GenOps -> Meta -> A.MonadicOp -> A.Expression -> CGen ()
-cgenMonadic ops _ A.MonadicSubtr e = call genSimpleMonadic ops "-" e
+cgenMonadic ops m A.MonadicSubtr e = call genFuncMonadic ops m "negate" e
+cgenMonadic ops _ A.MonadicMinus e = call genSimpleMonadic ops "-" e
 cgenMonadic ops _ A.MonadicBitNot e = call genSimpleMonadic ops "~" e
 cgenMonadic ops _ A.MonadicNot e = call genSimpleMonadic ops "!" e
 
diff --git a/ParseOccam.hs b/ParseOccam.hs
index 509b3f6..934c040 100644
--- a/ParseOccam.hs
+++ b/ParseOccam.hs
@@ -1010,7 +1010,8 @@ intrinsicFunctionSingle
 
 monadicOperator :: OccParser A.MonadicOp
 monadicOperator
-    =   do { reserved "-" <|> sMINUS; return A.MonadicSubtr }
+    =   do { reserved "-"; return A.MonadicSubtr }
+    <|> do { sMINUS; return A.MonadicMinus }
     <|> do { reserved "~" <|> sBITNOT; return A.MonadicBitNot }
     <|> do { sNOT; return A.MonadicNot }
     <?> "monadic operator"
diff --git a/RainParse.hs b/RainParse.hs
index d14b363..439e5e6 100644
--- a/RainParse.hs
+++ b/RainParse.hs
@@ -103,7 +103,7 @@ dyadicCompOp
 
 monadicArithOp :: RainParser (Meta,A.MonadicOp)
 monadicArithOp
-  = do {m <- reserved "-" ; return (m,A.MonadicSubtr) }
+  = do {m <- reserved "-" ; return (m,A.MonadicMinus) }
 
 
 
diff --git a/RainParseTest.hs b/RainParseTest.hs
index de141ba..3238509 100644
--- a/RainParseTest.hs
+++ b/RainParseTest.hs
@@ -124,13 +124,13 @@ testExprs =
 
   --Monadic operators:
 
-  ,passE ("-b", 101, Mon A.MonadicSubtr (Var "b") )
+  ,passE ("-b", 101, Mon A.MonadicMinus (Var "b") )
   ,failE ("+b")
-  ,passE ("a - - b", 102, Dy (Var "a") A.Minus (Mon A.MonadicSubtr $ Var "b") ) --TODO change this to MonadicMinus
-  ,passE ("a--b", 103, Dy (Var "a") A.Minus (Mon A.MonadicSubtr $ Var "b") ) --TODO change this to MonadicMinus
-  ,passE ("a---b", 104, Dy (Var "a") A.Minus (Mon A.MonadicSubtr $ Mon A.MonadicSubtr $ Var "b") ) --TODO change this to MonadicMinus
-  ,passE ("-b+c", 105, Dy (Mon A.MonadicSubtr $ Var "b") A.Plus (Var "c") )
-  ,passE ("-(b+c)", 106, Mon A.MonadicSubtr $ Dy (Var "b") A.Plus (Var "c") )
+  ,passE ("a - - b", 102, Dy (Var "a") A.Minus (Mon A.MonadicMinus $ Var "b") )
+  ,passE ("a--b", 103, Dy (Var "a") A.Minus (Mon A.MonadicMinus $ Var "b") )
+  ,passE ("a---b", 104, Dy (Var "a") A.Minus (Mon A.MonadicMinus $ Mon A.MonadicMinus $ Var "b") )
+  ,passE ("-b+c", 105, Dy (Mon A.MonadicMinus $ Var "b") A.Plus (Var "c") )
+  ,passE ("-(b+c)", 106, Mon A.MonadicMinus $ Dy (Var "b") A.Plus (Var "c") )
 
   --Casting: