diff --git a/REQUIRE b/REQUIRE
index 94237c0..9f97461 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1 +1,2 @@
 julia 0.5
+Compat 0.17
diff --git a/src/GeoInterface.jl b/src/GeoInterface.jl
index edae629..74fccff 100644
--- a/src/GeoInterface.jl
+++ b/src/GeoInterface.jl
@@ -2,6 +2,8 @@ __precompile__()
 
 module GeoInterface
 
+    using Compat
+
     export  AbstractPosition, Position,
             AbstractGeometry, AbstractGeometryCollection, GeometryCollection,
             AbstractPoint, Point,
@@ -20,7 +22,7 @@ module GeoInterface
             geometry, bbox, crs, properties,
             features
 
-    abstract AbstractPosition{T <: Real} <: AbstractVector{T}
+    @compat abstract type AbstractPosition{T <: Real} <: AbstractVector{T} end
     geotype(::AbstractPosition) = :Position
     xcoord(::AbstractPosition) = error("xcoord(::AbstractPosition) not defined.")
     ycoord(::AbstractPosition) = error("ycoord(::AbstractPosition) not defined.")
@@ -38,32 +40,32 @@ module GeoInterface
     Base.convert(::Type{Vector{Float64}}, p::AbstractPosition) = coordinates(p)
     # Base.linearindexing{T <: AbstractPosition}(::Type{T}) = LinearFast()
 
-    abstract AbstractGeometry
+    @compat abstract type AbstractGeometry end
     coordinates(obj::AbstractGeometry) = error("coordinates(::AbstractGeometry) not defined.")
 
-        abstract AbstractPoint <: AbstractGeometry
+        @compat abstract type AbstractPoint <: AbstractGeometry end
         geotype(::AbstractPoint) = :Point
 
-        abstract AbstractMultiPoint <: AbstractGeometry
+        @compat abstract type AbstractMultiPoint <: AbstractGeometry end
         geotype(::AbstractMultiPoint) = :MultiPoint
 
-        abstract AbstractLineString <: AbstractGeometry
+        @compat abstract type AbstractLineString <: AbstractGeometry end
         geotype(::AbstractLineString) = :LineString
 
-        abstract AbstractMultiLineString <: AbstractGeometry
+        @compat abstract type AbstractMultiLineString <: AbstractGeometry end
         geotype(::AbstractMultiLineString) = :MultiLineString
 
-        abstract AbstractPolygon <: AbstractGeometry
+        @compat abstract type AbstractPolygon <: AbstractGeometry end
         geotype(::AbstractPolygon) = :Polygon
 
-        abstract AbstractMultiPolygon <: AbstractGeometry
+        @compat abstract type AbstractMultiPolygon <: AbstractGeometry end
         geotype(::AbstractMultiPolygon) = :MultiPolygon
 
-        abstract AbstractGeometryCollection <: AbstractGeometry
+        @compat abstract type AbstractGeometryCollection <: AbstractGeometry end
         geotype(::AbstractGeometryCollection) = :GeometryCollection
         geometries(obj::AbstractGeometryCollection) = error("geometries(::AbstractGeometryCollection) not defined.")
 
-    abstract AbstractFeature
+    @compat abstract type AbstractFeature end
     geotype(::AbstractFeature) = :Feature
     geometry(obj::AbstractFeature) = error("geometry(::AbstractFeature) not defined.")
     # optional
@@ -71,7 +73,7 @@ module GeoInterface
     bbox(obj::AbstractFeature) = nothing
     crs(obj::AbstractFeature) = nothing
 
-    abstract AbstractFeatureCollection
+    @compat abstract type AbstractFeatureCollection end
     geotype(::AbstractFeatureCollection) = :FeatureCollection
     features(obj::AbstractFeatureCollection) = error("features(::AbstractFeatureCollection) not defined.")
     # optional
diff --git a/src/geotypes.jl b/src/geotypes.jl
index 749cbe8..ef982f7 100644
--- a/src/geotypes.jl
+++ b/src/geotypes.jl
@@ -1,7 +1,7 @@
 # Coordinate Reference System Objects
 # (has keys "type" and "properties")
 # TODO: Handle full CRS spec
-typealias CRS Dict{String,Any}
+const CRS = Dict{String,Any}
 
 # Bounding Boxes
 # The value of the bbox member must be a 2*n array,
@@ -11,9 +11,9 @@ typealias CRS Dict{String,Any}
 # The axes order of a bbox follows the axes order of geometries.
 # In addition, the coordinate reference system for the bbox is assumed to match
 # the coordinate reference system of the GeoJSON object of which it is a member.
-typealias BBox Vector{Float64}
+const BBox = Vector{Float64}
 
-typealias Position Vector{Float64}
+const Position = Vector{Float64}
 # (x, y, [z, ...]) - meaning of additional elements undefined.
 # In an object's contained geometries, Positions must have uniform dimensions.
 geotype(::Position) = :Position