diff --git a/Project.toml b/Project.toml
index d501113..a6ad801 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "JavaCall"
 uuid = "494afd89-becb-516b-aafa-70d2670c0337"
-version = "0.7.2"
+version = "0.7.3"
 
 [deps]
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
diff --git a/REQUIRE b/REQUIRE
deleted file mode 100644
index da6a941..0000000
--- a/REQUIRE
+++ /dev/null
@@ -1,3 +0,0 @@
-julia 0.7
-DataStructures
-@windows WinReg
diff --git a/src/jvm.jl b/src/jvm.jl
index 37606e6..4d47a80 100644
--- a/src/jvm.jl
+++ b/src/jvm.jl
@@ -152,6 +152,10 @@ end
 addOpts(s::String) = isloaded() ? @warn("JVM already initialised. This call has no effect") : push!(opts, s)
 
 function init()
+    if VERSION ≥ v"1.3" && get(ENV, "JULIA_COPY_STACKS", "") ∉ ("1", "yes")
+        @warn("JavaCall needs the environment variable `JULIA_COPY_STACKS` to be `1` or `yes`. "*
+              "Calling the JVM may result in undefined behavior.")
+    end
     if isempty(cp)
         init(opts)
     else