diff --git a/src/differentiate.jl b/src/differentiate.jl
index 72192e1..d34c386 100644
--- a/src/differentiate.jl
+++ b/src/differentiate.jl
@@ -124,6 +124,7 @@ symbolic_derivative_1arg_list = [
     ( :exp,         :(  exp(x)                                  ))
     ( :exp2,        :(  log(2) * exp2(x)                        ))
     ( :expm1,       :(  exp(x)                                  ))
+    ( :mod2pi,      :(  1                                       ))
     ( :sin,         :(  cos(x)                                  ))
     ( :cos,         :( -sin(x)                                  ))
     ( :tan,         :(  (1 + tan(x)^2)                          ))