diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dbca8a0..5a29b32 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,8 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.0'
+          - '1.3'
+          - '1.6'
           - '1'
           - 'nightly'
         os:
diff --git a/Project.toml b/Project.toml
index c962cf8..49d8e90 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "DiffRules"
 uuid = "b552c78f-8df3-52c6-915a-8e097449b14b"
-version = "1.6.0"
+version = "1.7.0"
 
 [deps]
 LogExpFunctions = "2ab3a3ac-af41-5b50-aa03-7779005ae688"
@@ -12,7 +12,7 @@ SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 LogExpFunctions = "0.3.2"
 NaNMath = "0.3"
 SpecialFunctions = "0.8, 0.9, 0.10, 1.0, 2"
-julia = "1"
+julia = "1.3"
 
 [extras]
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
diff --git a/src/rules.jl b/src/rules.jl
index d70b71e..c6f8e48 100644
--- a/src/rules.jl
+++ b/src/rules.jl
@@ -83,11 +83,7 @@ _abs_deriv(x) = signbit(x) ? -one(x) : one(x)
 @define_diffrule Base.:\(x, y) = :( -($y / $x / $x)    ), :( one($y) / ($x)     )
 @define_diffrule Base.:^(x, y) = :( $y * ($x^($y - 1)) ), :( ($x isa Real && $x<=0) ? Base.oftype(float($x), NaN) : ($x^$y)*log($x) )
 
-if VERSION < v"0.7-"
-    @define_diffrule Base.atan2(x, y)   = :( $y / ($x^2 + $y^2)                                 ), :( -$x / ($x^2 + $y^2)                                                     )
-else
-    @define_diffrule Base.atan(x, y)    = :( $y / ($x^2 + $y^2)                                 ), :( -$x / ($x^2 + $y^2)                                                     )
-end
+@define_diffrule Base.atan(x, y)    = :( $y / ($x^2 + $y^2)                                 ), :( -$x / ($x^2 + $y^2)                                                     )
 @define_diffrule Base.hypot(x, y)  = :( $x / hypot($x, $y)                                      ), :(  $y / hypot($x, $y)                                                     )
 @define_diffrule Base.log(b, x)    = :( log($x) * inv(-log($b)^2 * $b)                          ), :( inv($x) / log($b)                                                       )