diff --git a/src/context.jl b/src/context.jl
index 7c77cec2..aea70d4d 100644
--- a/src/context.jl
+++ b/src/context.jl
@@ -8,7 +8,10 @@ type Context
             @check api.clRetainContext(ctx_id)
         end
         ctx = new(ctx_id)
-        finalizer(ctx, c -> release!(c))
+        finalizer(ctx, c -> begin
+            retain || _deletecached!(c);
+            release!(c)
+        end )
         return ctx 
     end
 end
diff --git a/src/macros.jl b/src/macros.jl
index 9b83a336..dc8b0af6 100644
--- a/src/macros.jl
+++ b/src/macros.jl
@@ -97,3 +97,29 @@ macro str_info(what, arg1, arg2)
         bytestring(convert(Ptr{CL_char}, result))
     end
 end
+
+function _version_test(qm, elem :: Symbol, ex :: Expr, version :: VersionNumber)
+    @assert qm == :?
+    @assert ex.head == :(:)
+    @assert length(ex.args) == 2
+
+    esc(quote
+        if OpenCL.check_version($elem, $version)
+            $(ex.args[1])
+        else
+            $(ex.args[2])
+        end
+    end)
+end
+
+macro min_v11(qm, elem, ex)
+    _version_test(qm, elem, ex, v"1.1")
+end
+
+macro min_v12(qm, elem, ex)
+    _version_test(qm, elem, ex, v"1.2")
+end
+
+macro min_v20(qm, elem, ex)
+    _version_test(qm, elem, ex, v"2.0")
+end
diff --git a/src/queue.jl b/src/queue.jl
index b86dc7ff..6bf25f05 100644
--- a/src/queue.jl
+++ b/src/queue.jl
@@ -8,7 +8,10 @@ type CmdQueue
             @check api.clRetainCommandQueue(q_id)
         end
         q = new(q_id)
-        finalizer(q, x -> release!(x))
+        finalizer(q, x -> begin
+            retain || _deletecached!(q)
+            release!(x)
+        end )
         return q
     end
 end 
diff --git a/src/util.jl b/src/util.jl
index c5d1d862..666abc12 100644
--- a/src/util.jl
+++ b/src/util.jl
@@ -5,7 +5,17 @@ function create_compute_context()
     return (device, ctx, queue)
 end
 
-opencl_version(p::Platform) = api.parse_version(p[:version])
-opencl_version(d::Device)   = opencl_version(d[:platform])
-opencl_version(c::Context)  = opencl_version(first(devices(c)))
-opencl_version(q::CmdQueue) = opencl_version(q[:context])
+opencl_version(p :: Platform) = api.parse_version(p[:version])
+opencl_version(d :: Device)   = api.parse_version(d[:version])
+opencl_version(c :: Context)  = opencl_version(first(devices(c)))
+opencl_version(q :: CmdQueue) = opencl_version(q[:device])
+
+const _versionDict = Dict{Ptr{Void}, VersionNumber}()
+
+_deletecached!(obj) = delete!(_versionDict, pointer(obj))
+
+function check_version(obj, version :: VersionNumber)
+    version <= get!(_versionDict, pointer(obj)) do
+        opencl_version(obj)
+    end
+end
diff --git a/test/runtests.jl b/test/runtests.jl
index c057e3ea..9323f498 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -3,6 +3,7 @@ const tests = [
             "context"
             "device"
             "cmdqueue"
+            "macros"
             "event"
             "program"
             "kernel"
diff --git a/test/test_macros.jl b/test/test_macros.jl
new file mode 100644
index 00000000..90e87853
--- /dev/null
+++ b/test/test_macros.jl
@@ -0,0 +1,76 @@
+using FactCheck
+using Base.Test
+
+import OpenCL
+const cl = OpenCL
+
+facts("OpenCL.Macros") do
+
+    context("OpenCL.Macros version platform") do
+        for platform in cl.platforms()
+
+            version = cl.opencl_version(platform)
+
+            v11 = cl.@min_v11? platform true : false
+            v12 = cl.@min_v12? platform true : false
+            v20 = cl.@min_v20? platform true : false
+
+            if version == v"1.0"
+                @fact v11 => false
+                @fact v12 => false
+                @fact v20 => false
+
+            elseif version == v"1.1"
+                @fact v11 => true
+                @fact v12 => false
+                @fact v20 => false
+
+            elseif version == v"1.2"
+                @fact v11 => true
+                @fact v12 => true
+                @fact v20 => false
+
+            elseif version == v"2.0"
+                @fact v11 => true
+                @fact v12 => true
+                @fact v20 => true
+
+            end
+        end
+    end
+
+    context("OpenCL.Macros version device") do
+        for platform in cl.platforms()
+            for device in cl.devices(platform)
+                version = cl.opencl_version(device)
+
+                v11 = cl.@min_v11? device true : false
+                v12 = cl.@min_v12? device true : false
+                v20 = cl.@min_v20? device true : false
+
+                if version == v"1.0"
+                    @fact v11 => false
+                    @fact v12 => false
+                    @fact v20 => false
+
+                elseif version == v"1.1"
+                    @fact v11 => true
+                    @fact v12 => false
+                    @fact v20 => false
+
+                elseif version == v"1.2"
+                    @fact v11 => true
+                    @fact v12 => true
+                    @fact v20 => false
+
+                elseif version == v"2.0"
+                    @fact v11 => true
+                    @fact v12 => true
+                    @fact v20 => true
+
+                end
+            end
+        end
+    end
+end
+