diff --git a/Makefile b/Makefile
index 99a4c56f..f0171115 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
+RACK_DIR ?= .
 VERSION = master
-RACK_DIR = .
 
 FLAGS += \
 	-Iinclude \
diff --git a/compile.mk b/compile.mk
index f2f8b812..4479af85 100644
--- a/compile.mk
+++ b/compile.mk
@@ -1,16 +1,21 @@
-ifdef VERSION
-	FLAGS += -DVERSION=$(VERSION)
+ifndef RACK_DIR
+$(error RACK_DIR is not defined in Makefile)
+endif
+
+ifndef VERSION
+$(error VERSION is not defined in Makefile)
 endif
 
-RACK_DIR ?= .
 include $(RACK_DIR)/arch.mk
 
+FLAGS += -DVERSION=$(VERSION)
 # Generate dependency files alongside the object files
 FLAGS += -MMD -MP
 FLAGS += -g
 # Optimization
 FLAGS += -O3 -march=nocona -ffast-math -fno-finite-math-only
 FLAGS += -Wall -Wextra -Wno-unused-parameter
+
 ifneq ($(ARCH), mac)
 	CXXFLAGS += -Wsuggest-override
 endif
diff --git a/dep.mk b/dep.mk
new file mode 100644
index 00000000..cfe09c48
--- /dev/null
+++ b/dep.mk
@@ -0,0 +1,27 @@
+include $(RACK_DIR)/arch.mk
+
+LOCAL ?= .
+FLAGS += -g -O3 -march=nocona
+
+ifeq ($(ARCH), mac)
+	FLAGS += -mmacosx-version-min=10.7 -stdlib=libc++
+	LDFLAGS += -mmacosx-version-min=10.7 -stdlib=libc++
+endif
+
+CFLAGS += $(FLAGS)
+CXXFLAGS += $(FLAGS)
+export CFLAGS
+export CXXFLAGS
+export LDFLAGS
+
+# Commands
+WGET := curl -OL
+UNTAR := tar xf
+UNZIP := unzip
+MAKE := make
+CONFIGURE := ./configure --prefix="$(realpath $(LOCAL))"
+ifeq ($(ARCH), win)
+	CMAKE := cmake -G 'MSYS Makefiles'
+else
+	CMAKE := cmake
+endif
diff --git a/dep/Makefile b/dep/Makefile
index 5fe02eab..34e349e2 100755
--- a/dep/Makefile
+++ b/dep/Makefile
@@ -1,31 +1,6 @@
-LOCAL = $(shell pwd)
+RACK_DIR ?= ..
 
-# Arch-specifics
-include ../arch.mk
-
-FLAGS += -g -O3 -march=nocona
-
-ifeq ($(ARCH),mac)
-	FLAGS += -mmacosx-version-min=10.7 -stdlib=libc++
-	LDFLAGS += -mmacosx-version-min=10.7 -stdlib=libc++
-endif
-
-CFLAGS += $(FLAGS)
-CXXFLAGS += $(FLAGS)
-export CFLAGS
-export CXXFLAGS
-export LDFLAGS
-
-
-# Commands
-WGET = curl -OL
-UNTAR = tar xf
-UNZIP = unzip
-ifeq ($(ARCH),win)
-	CMAKE = cmake -G 'MSYS Makefiles'
-else
-	CMAKE = cmake
-endif
+include $(RACK_DIR)/dep.mk
 
 # Libraries
 ifeq ($(ARCH),lin)
@@ -96,14 +71,14 @@ $(glfw):
 $(jansson):
 	$(WGET) http://www.digip.org/jansson/releases/jansson-2.10.tar.gz
 	$(UNTAR) jansson-2.10.tar.gz
-	cd jansson-2.10 && ./configure --prefix="$(LOCAL)"
+	cd jansson-2.10 && $(CONFIGURE)
 	$(MAKE) -C jansson-2.10
 	$(MAKE) -C jansson-2.10 install
 
 $(libspeexdsp):
 	$(WGET) https://vcvrack.com/downloads/dep/speexdsp-SpeexDSP-1.2rc3.tgz
 	$(UNTAR) speexdsp-SpeexDSP-1.2rc3.tgz
-	cd speexdsp-SpeexDSP-1.2rc3 && ./configure --prefix="$(LOCAL)"
+	cd speexdsp-SpeexDSP-1.2rc3 && $(CONFIGURE)
 	$(MAKE) -C speexdsp-SpeexDSP-1.2rc3
 	$(MAKE) -C speexdsp-SpeexDSP-1.2rc3 install
 
@@ -117,7 +92,7 @@ $(openssl):
 $(libcurl): $(openssl)
 	$(WGET) https://github.com/curl/curl/releases/download/curl-7_56_0/curl-7.56.0.tar.gz
 	$(UNTAR) curl-7.56.0.tar.gz
-	cd curl-7.56.0 && ./configure --prefix="$(LOCAL)" \
+	cd curl-7.56.0 && $(CONFIGURE) \
 		--disable-ftp --disable-file --disable-ldap --disable-ldaps --disable-rtsp --disable-proxy --disable-dict --disable-telnet --disable-tftp --disable-pop3 --disable-imap --disable-smb --disable-smtp --disable-gopher --disable-manual \
 		--without-zlib --without-libpsl --without-libmetalink --without-libssh2 --without-librtmp --without-winidn --without-libidn2 --without-nghttp2 \
 		--without-ca-bundle --with-ca-fallback --with-ssl="$(LOCAL)"
@@ -127,14 +102,14 @@ $(libcurl): $(openssl)
 $(libzip):
 	$(WGET) https://nih.at/libzip/libzip-1.2.0.tar.gz
 	$(UNTAR) libzip-1.2.0.tar.gz
-	cd libzip-1.2.0 && ./configure --prefix="$(LOCAL)"
+	cd libzip-1.2.0 && $(CONFIGURE)
 	$(MAKE) -C libzip-1.2.0
 	$(MAKE) -C libzip-1.2.0 install
 
 $(rtmidi):
 	$(WGET) https://vcvrack.com/downloads/dep/rtmidi.tgz
 	$(UNTAR) rtmidi.tgz
-	cd rtmidi && ./configure --prefix="$(LOCAL)"
+	cd rtmidi && $(CONFIGURE)
 	$(MAKE) -C rtmidi
 	$(MAKE) -C rtmidi install
 
diff --git a/plugin.mk b/plugin.mk
index 37776dfc..61903990 100644
--- a/plugin.mk
+++ b/plugin.mk
@@ -1,12 +1,15 @@
-RACK_DIR ?= ../..
-
-FLAGS += -fPIC \
-	-I$(RACK_DIR)/include -I$(RACK_DIR)/dep/include
+ifndef RACK_DIR
+$(error RACK_DIR is not defined in Makefile)
+endif
 
-ifdef SLUG
-	FLAGS += -DSLUG=$(SLUG)
+ifndef SLUG
+$(error SLUG is not defined in Makefile)
 endif
 
+FLAGS += -DSLUG=$(SLUG)
+FLAGS += -fPIC
+FLAGS += -I$(RACK_DIR)/include -I$(RACK_DIR)/dep/include
+
 
 include $(RACK_DIR)/arch.mk