diff --git a/configure b/configure
index 856d590..5644912 100755
--- a/configure
+++ b/configure
@@ -1,3 +1,21 @@
 #!/bin/sh -e
 
-cp config.mk.in config.mk
+ENV="$1"
+
+if [ -z "$ENV" ]; then
+    ENV='build'
+fi
+
+CONFIG="env/$ENV.mk"
+
+if [ ! -f "$CONFIG" ]; then
+    echo >&2 "ERROR: file "$CONFIG" does not exist"
+    exit 1
+fi
+
+if [ -f 'config.mk' ]; then
+    echo >&2 "ERROR: file 'config.mk' already exist"
+    exit 1
+fi
+
+cp "$CONFIG" 'config.mk'
diff --git a/config.mk.in b/env/build.mk
similarity index 100%
rename from config.mk.in
rename to env/build.mk
diff --git a/env/test.mk b/env/test.mk
new file mode 100644
index 0000000..3175952
--- /dev/null
+++ b/env/test.mk
@@ -0,0 +1 @@
+export CCPREFIX =