diff --git a/src/ArgCheck.jl b/src/ArgCheck.jl
index a1a2d41..7276554 100644
--- a/src/ArgCheck.jl
+++ b/src/ArgCheck.jl
@@ -22,7 +22,6 @@ macro argcheck(code,args...)
 end
 
 function argcheck(ex, args...)
-    ex = canonicalize(ex)
     if isexpr(ex, :comparison)
         argcheck_comparison(ex, args...)
     elseif is_simple_call(ex)
@@ -67,7 +66,9 @@ function argcheck_call(ex, args...)
     )
     quote
         $(assignments...)
-        if !($condition)
+        if $condition
+            nothing
+        else
             throw($err)
         end
     end
@@ -77,11 +78,11 @@ function argcheck_comparison(ex, args...)
     exprs = ex.args[1:2:end]
     ops = ex.args[2:2:end]
     variables = [gensym() for _ in 1:length(exprs)]
-    ret = quote end
+    ret = []
     rhs = exprs[1]
     vrhs = variables[1]
     assignment = Expr(:(=), vrhs, esc(rhs))
-    push!(ret.args, assignment)
+    push!(ret, assignment)
     for i in eachindex(ops)
         op = ops[i]
         lhs = rhs
@@ -96,13 +97,15 @@ function argcheck_comparison(ex, args...)
             vlhs, vrhs, esc.(args)...)
         reti = quote
             $assignment
-            if !($condition)
+            if $condition
+                nothing
+            else
                 throw($err)
             end
         end
-        append!(ret.args, reti.args)
+        append!(ret, reti.args)
     end
-    ret
+    Expr(:block, ret...)
 end
 
 function build_error(code, T::Type{<:Exception}, args...) 
diff --git a/test/runtests.jl b/test/runtests.jl
index fbba7c3..a4d1aae 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -68,28 +68,38 @@ end
 end
 
 # exotic cases
-f(args...) = false
-t(args...) = true
-@argcheck t()
-@test_throws ArgumentError @argcheck f()
-
-op() = (x,y) -> x < y
-x = 1; y = 2
-@argcheck op()(x,y)
-@test_throws ArgumentError @argcheck op()(y,x)
-@test_throws ArgumentError @argcheck begin false end
-@test_throws DivideError @argcheck f() DivideError()
-
+struct MyError <: Exception
+    msg::String
+end
 struct MyExoticError <: Exception
     a::Int
     b::Int
 end
 
-err = @catch_exception_object @argcheck false MyExoticError(1,2)
-@test err === MyExoticError(1,2)
+falsy(args...) = false
+truthy(args...) = true
 
-struct MyError <: Exception
-    msg::String
+@testset "exotic cases" begin
+    @argcheck truthy()
+    @test_throws ArgumentError @argcheck falsy()
+
+    @argcheck begin
+        multi_line_true_is_no_problem = true
+        multi_line_true_is_no_problem
+    end
+    @test_throws DimensionMismatch @argcheck let
+        falsy(1,2)
+    end DimensionMismatch
+
+    
+    op() = (x,y) -> x < y
+    x = 1; y = 2
+    @argcheck op()(x,y)
+    @test_throws ArgumentError @argcheck op()(y,x)
+    @test_throws ArgumentError @argcheck begin false end
+    @test_throws DivideError @argcheck falsy() DivideError()
+    err = @catch_exception_object @argcheck false MyExoticError(1,2)
+    @test err === MyExoticError(1,2)
 end
 
 @testset "error message comparison" begin
@@ -127,11 +137,15 @@ end
     @test contains(msg, "≦")
 end
 
-@testset "error message call" begin
+# In 
+# We can't wrap this in @testset on julia v0.6
+# because of https://github.com/JuliaLang/julia/issues/24316
+# @testset "error message call" begin
+let
     x = 1.2
     y = 1.34
     z = -345.234
-    err = @catch_exception_object @argcheck f([x y; z z])
+    err = @catch_exception_object @argcheck falsy([x y; z z])
     msg = err.msg
     @test contains(msg, string(x))
     @test contains(msg, string(z))