diff --git a/Makefile b/Makefile
index 3415965..8219079 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,7 @@ path_doc := ./doc
 
 combine := $(path_tools)/combine
 compiler := $(path_tools)/compiler.jar
-
+path_externs_internal := $(path_build)/externs-internal.js
 
 .PHONY: combine min doc test test-combine clean distclean
 
@@ -56,17 +56,23 @@ perf: default $(perf_tests)
 perf-%.js: default
 	@node $@
 
-# minificatino process uses Google Closure compiler
+# externs for compilation process
+$(path_externs_internal): | mkbuild
+	$(path_tools)/mkexterns > $@
+
+# minification process uses Google Closure compiler
 min: build/ease.min.js build/ease-full.min.js $(path_build)/browser-test-min.html \
-	$(path_tools)/externs-global.js | combine
+	| combine
 $(compiler):
 	wget -O- http://closure-compiler.googlecode.com/files/compiler-latest.tar.gz \
 		| tar -C $(path_tools) -xzv compiler.jar
-build/%.min.js: build/%.js $(compiler)
+build/%.min.js: build/%.js $(path_tools)/externs-global.js  $(path_externs_internal) \
+	$(compiler)
 	cat $(path_tools)/license.tpl > $@
 	java -jar $(compiler) \
 		--warning_level VERBOSE \
 		--externs $(path_tools)/externs-global.js \
+		--externs $(path_build)/externs-internal.js \
 		--js $< >> $@ || rm $@
 
 install: doc-info
diff --git a/tools/mkexterns b/tools/mkexterns
new file mode 100755
index 0000000..c8b841c
--- /dev/null
+++ b/tools/mkexterns
@@ -0,0 +1,23 @@
+#!/bin/bash
+#
+# Because this project consists of a bunch of CommonJS modules, the constructors
+# have restricted scope. This means that they cannot be used as types in other
+# modules. Therefore, to permit this, we must generate an extern file containing
+# basic definitions of each.
+#
+# This is used only for compilation and is otherwise completely unnecessary. As
+# such, to reduce maintenance overhead, the creation of this file is automated.
+# #
+
+# all CamelCase modules are likely to be ctors
+modules=$( ls lib/ \
+    | sed 's/lib\/\|\.js//' \
+    | grep -vP '^[a-z]'
+)
+
+# simple definition for now (we'll worry about members later)
+for module in $modules; do
+    echo "/** @constructor */"
+    echo "function $module() {};"
+    echo
+done