diff --git a/compiler+runtime/include/cpp/jank/runtime/context.hpp b/compiler+runtime/include/cpp/jank/runtime/context.hpp
index b7eccbc8c..b9c4c1453 100644
--- a/compiler+runtime/include/cpp/jank/runtime/context.hpp
+++ b/compiler+runtime/include/cpp/jank/runtime/context.hpp
@@ -141,7 +141,7 @@ namespace jank::runtime
     /* TODO: This needs to be a dynamic var. */
     native_unordered_map<native_persistent_string, native_vector<native_persistent_string>>
       module_dependencies;
-    native_persistent_string output_dir;
+    native_persistent_string binary_cache_dir;
     module::loader module_loader;
 
     var_ptr current_file_var{};
diff --git a/compiler+runtime/include/cpp/jank/util/cli.hpp b/compiler+runtime/include/cpp/jank/util/cli.hpp
index 7eae043a6..17e3ee6d5 100644
--- a/compiler+runtime/include/cpp/jank/util/cli.hpp
+++ b/compiler+runtime/include/cpp/jank/util/cli.hpp
@@ -28,7 +28,6 @@ namespace jank::util::cli
     native_vector<native_persistent_string> libs;
 
     /* Compilation. */
-    native_transient_string compilation_path{ "classes" };
     native_integer optimization_level{};
 
     /* Run command. */
diff --git a/compiler+runtime/include/cpp/jank/util/dir.hpp b/compiler+runtime/include/cpp/jank/util/dir.hpp
index d7fa9493f..0747aeb48 100644
--- a/compiler+runtime/include/cpp/jank/util/dir.hpp
+++ b/compiler+runtime/include/cpp/jank/util/dir.hpp
@@ -7,7 +7,13 @@ namespace jank::util
   native_persistent_string const &user_home_dir();
   native_persistent_string const &user_cache_dir();
   native_persistent_string const &user_config_dir();
-  native_persistent_string const &binary_cache_dir();
+  native_persistent_string const &
+  binary_cache_dir(native_integer const optimization_level,
+                   native_vector<native_persistent_string> const &includes,
+                   native_vector<native_persistent_string> const &defines);
 
-  native_persistent_string const &binary_version();
+  native_persistent_string const &
+  binary_version(native_integer const optimization_level,
+                 native_vector<native_persistent_string> const &includes,
+                 native_vector<native_persistent_string> const &defines);
 }
diff --git a/compiler+runtime/src/cpp/jank/runtime/context.cpp b/compiler+runtime/src/cpp/jank/runtime/context.cpp
index dcb72a871..e461e0706 100644
--- a/compiler+runtime/src/cpp/jank/runtime/context.cpp
+++ b/compiler+runtime/src/cpp/jank/runtime/context.cpp
@@ -8,7 +8,6 @@
 #include <llvm/TargetParser/Host.h>
 
 #include <fmt/compile.h>
-#include <regex>
 
 #include <jank/native_persistent_string/fmt.hpp>
 #include <jank/read/lex.hpp>
@@ -23,6 +22,7 @@
 #include <jank/util/mapped_file.hpp>
 #include <jank/util/process_location.hpp>
 #include <jank/util/clang_format.hpp>
+#include <jank/util/dir.hpp>
 #include <jank/codegen/llvm_processor.hpp>
 #include <jank/profile/time.hpp>
 
@@ -41,7 +41,9 @@ namespace jank::runtime
 
   context::context(util::cli::options const &opts)
     : jit_prc{ opts }
-    , output_dir{ opts.compilation_path }
+    , binary_cache_dir{ util::binary_cache_dir(opts.optimization_level,
+                                               opts.include_dirs,
+                                               opts.define_macros) }
     , module_loader{ *this, opts.module_path }
   {
     auto const core(intern_ns(make_box<obj::symbol>("clojure.core")));
@@ -296,7 +298,7 @@ namespace jank::runtime
   {
     profile::timer const timer{ fmt::format("write_module {}", codegen_ctx->module_name) };
     boost::filesystem::path const module_path{
-      fmt::format("{}/{}.o", output_dir, module::module_to_path(codegen_ctx->module_name))
+      fmt::format("{}/{}.o", binary_cache_dir, module::module_to_path(codegen_ctx->module_name))
     };
     boost::filesystem::create_directories(module_path.parent_path());
 
diff --git a/compiler+runtime/src/cpp/jank/runtime/module/loader.cpp b/compiler+runtime/src/cpp/jank/runtime/module/loader.cpp
index 1e9892866..49544731b 100644
--- a/compiler+runtime/src/cpp/jank/runtime/module/loader.cpp
+++ b/compiler+runtime/src/cpp/jank/runtime/module/loader.cpp
@@ -289,10 +289,10 @@ namespace jank::runtime::module
     native_transient_string paths{ ps };
     paths += fmt::format(":{}", (jank_path / "classes").string());
     paths += fmt::format(":{}", (jank_path / "../src/jank").string());
-    paths += fmt::format(":{}", rt_ctx.output_dir);
+    paths += fmt::format(":{}", rt_ctx.binary_cache_dir);
     this->paths = paths;
 
-    //fmt::println("module paths: {}", paths);
+    // fmt::println("module paths: {}", paths);
 
     size_t start{};
     size_t i{ paths.find(module_separator, start) };
diff --git a/compiler+runtime/src/cpp/jank/util/cli.cpp b/compiler+runtime/src/cpp/jank/util/cli.cpp
index cda025942..4975e7a7f 100644
--- a/compiler+runtime/src/cpp/jank/util/cli.cpp
+++ b/compiler+runtime/src/cpp/jank/util/cli.cpp
@@ -21,9 +21,6 @@ namespace jank::util::cli
       fmt::format(
         "A {} separated list of directories, JAR files, and ZIP files to search for modules.",
         runtime::module::loader::module_separator));
-    cli.add_option("--output-dir",
-                   opts.compilation_path,
-                   "The base directory where compiled modules are written.");
     cli.add_flag("--profile", opts.profiler_enabled, "Enable compiler and runtime profiling.");
     cli.add_option("--profile-output",
                    opts.profiler_file,
diff --git a/compiler+runtime/src/cpp/jank/util/dir.cpp b/compiler+runtime/src/cpp/jank/util/dir.cpp
index 5eec1db6b..f57002875 100644
--- a/compiler+runtime/src/cpp/jank/util/dir.cpp
+++ b/compiler+runtime/src/cpp/jank/util/dir.cpp
@@ -6,6 +6,7 @@
 #include <jank/native_persistent_string/fmt.hpp>
 #include <jank/util/dir.hpp>
 #include <jank/util/sha256.hpp>
+#include <jank/util/string_builder.hpp>
 
 namespace jank::util
 {
@@ -61,7 +62,10 @@ namespace jank::util
     return res;
   }
 
-  native_persistent_string const &binary_cache_dir()
+  native_persistent_string const &
+  binary_cache_dir(native_integer const optimization_level,
+                   native_vector<native_persistent_string> const &includes,
+                   native_vector<native_persistent_string> const &defines)
   {
     static native_persistent_string res;
     if(!res.empty())
@@ -69,7 +73,8 @@ namespace jank::util
       return res;
     }
 
-    return res = fmt::format("{}/{}", user_cache_dir(), binary_version());
+    return res
+      = fmt::format("{}/{}", "target", binary_version(optimization_level, includes, defines));
   }
 
   /* The binary version is composed of two things:
@@ -83,7 +88,10 @@ namespace jank::util
    * every module. I think this is much safer than trying to reconcile ABI
    * changes more granularly.
    */
-  native_persistent_string const &binary_version()
+  native_persistent_string const &
+  binary_version(native_integer const optimization_level,
+                 native_vector<native_persistent_string> const &includes,
+                 native_vector<native_persistent_string> const &defines)
   {
     static native_persistent_string res;
     if(!res.empty())
@@ -91,8 +99,25 @@ namespace jank::util
       return res;
     }
 
-    auto const input(
-      fmt::format("{}.{}.{}", JANK_VERSION, clang::getClangRevision(), JANK_JIT_FLAGS));
+    string_builder sb;
+    for(auto const &inc : includes)
+    {
+      sb(inc);
+    }
+
+    sb(".");
+
+    for(auto const &def : defines)
+    {
+      sb(def);
+    }
+
+    auto const input(fmt::format("{}.{}.{}.{}.{}",
+                                 JANK_VERSION,
+                                 clang::getClangRevision(),
+                                 JANK_JIT_FLAGS,
+                                 optimization_level,
+                                 sb.release()));
     res = fmt::format("{}-{}", llvm::sys::getDefaultTargetTriple(), util::sha256(input));
 
     //fmt::println("binary_version {}", res);