diff --git a/LexRain.x b/LexRain.x
index b463033..cc4a8d5 100644
--- a/LexRain.x
+++ b/LexRain.x
@@ -33,8 +33,8 @@ $hexDigit = [0-9 a-f A-F]
 
 @reserved = "[" | "]" | "(" | ")" | "{" | "}"
           | ":" | "==" | "," | ";"
-          | "?" | "!" | "=" | "+=" | "-=" | "*=" | "/="
-          | "+" | "-" | "*" | "/"
+          | "?" | "!" | "=" | "+=" | "-=" | "*=" | "/=" | "%="
+          | "+" | "-" | "*" | "/" | "%"
           | ">=" | "<="
           | "<" | ">"
           | "process" | "pareach" | "seqeach" | "par" | "seq" 
diff --git a/RainParse.hs b/RainParse.hs
index 6a6e4be..74b68e4 100644
--- a/RainParse.hs
+++ b/RainParse.hs
@@ -92,6 +92,7 @@ dyadicArithOp
     <|> do {m <- reserved "-" ; return (m,A.Minus) }
     <|> do {m <- reserved "*" ; return (m,A.Times) }
     <|> do {m <- reserved "/" ; return (m,A.Div) }
+    <|> do {m <- reserved "%" ; return (m,A.Rem) }
 
 dyadicCompOp :: RainParser (Meta,A.DyadicOp)
 dyadicCompOp
@@ -256,6 +257,9 @@ assignOp :: RainParser (Meta, Maybe A.DyadicOp)
 assignOp
   = do {m <- reserved "+=" ; return (m,Just A.Plus)}
     <|> do {m <- reserved "-=" ; return (m,Just A.Minus)}
+    <|> do {m <- reserved "*=" ; return (m,Just A.Times)}
+    <|> do {m <- reserved "/=" ; return (m,Just A.Div)}
+    <|> do {m <- reserved "%=" ; return (m,Just A.Rem)}
     <|> do {m <- reserved "=" ; return (m,Nothing)}	
     --TODO the rest
 
diff --git a/RainParseTest.hs b/RainParseTest.hs
index 221be3b..186cc29 100644
--- a/RainParseTest.hs
+++ b/RainParseTest.hs
@@ -103,6 +103,7 @@ testExprs =
 
   --Dyadic operators:
   ,passE ("b + c", 0 ,Dy (Var "b") A.Plus (Var "c") )
+  ,passE ("b % c", 0 ,Dy (Var "b") A.Rem (Var "c") )
   ,passE ("b == c", 1 ,Dy (Var "b") A.Eq (Var "c") )
   ,passE ("(b + c)", 2 ,Dy (Var "b") A.Plus (Var "c") )
   ,passE ("(b == c)", 3 ,Dy (Var "b") A.Eq (Var "c") )