diff --git a/Makefile b/Makefile
index f40b9264..b3f66362 100644
--- a/Makefile
+++ b/Makefile
@@ -6,23 +6,45 @@
 # of patent rights can be found in the PATENTS file in the same directory.
 
 FILES=src/__tests__/Layout-test.c src/Layout.c src/Layout-test-utils.c
+JAVA_LIB_DIR=lib
+
+ifeq ($(OS),Windows_NT)
+	C_TEST_EXE=./c_test.exe
+	ENVSEP=";"
+	WGET=wget --no-check-certificate
+	LLDB=gdb
+else
+	C_TEST_EXE=./c_test
+	ENVSEP=":"
+	WGET=wget
+	LLDB=lldb
+endif
 
 all: c c_test java java_test
 
 c: transpile_all
 
 c_test: c
-	@gcc -std=c99 -Werror -Wno-padded $(FILES) -lm && ./a.out
-	@rm a.out
+	@gcc -std=c99 -Werror -Wno-padded $(FILES) -lm -o "$(C_TEST_EXE)" && "$(C_TEST_EXE)"
+	@rm "$(C_TEST_EXE)"
 
-java: transpile_all src/java
-	@if [ ! -f lib/junit4.jar ]; then mkdir lib/; wget -O lib/junit4.jar http://search.maven.org/remotecontent?filepath=junit/junit/4.10/junit-4.10.jar; fi
-	@if [ ! -f lib/jsr305.jar ]; then mkdir lib/; wget -O lib/jsr305.jar http://search.maven.org/remotecontent?filepath=net/sourceforge/findbugs/jsr305/1.3.7/jsr305-1.3.7.jar; fi
-	@if [ ! -f lib/infer-annotations-1.4.jar ]; then mkdir lib/; wget -O lib/infer-annotations-1.4.jar https://github.com/facebook/buck/raw/027ffe2b230c08cad7b340646c6f801bd6dabc78/third-party/java/infer-annotations/infer-annotations-1.4.jar; fi
-	@javac -cp ./lib/junit4.jar:./lib/jsr305.jar:./lib/infer-annotations-1.4.jar -sourcepath ./src/java/src:./src/java/tests src/java/tests/com/facebook/csslayout/*.java
+$(JAVA_LIB_DIR):
+	mkdir $(JAVA_LIB_DIR)
+
+$(JAVA_LIB_DIR)/junit4.jar: | $(JAVA_LIB_DIR)
+	$(WGET) -O $(JAVA_LIB_DIR)/junit4.jar http://search.maven.org/remotecontent?filepath=junit/junit/4.10/junit-4.10.jar
+
+$(JAVA_LIB_DIR)/jsr305.jar: | $(JAVA_LIB_DIR)
+	$(WGET) -O $(JAVA_LIB_DIR)/jsr305.jar http://search.maven.org/remotecontent?filepath=net/sourceforge/findbugs/jsr305/1.3.7/jsr305-1.3.7.jar
+
+$(JAVA_LIB_DIR)/infer-annotations-1.4.jar: | $(JAVA_LIB_DIR)
+	$(WGET) -O $(JAVA_LIB_DIR)/infer-annotations-1.4.jar https://github.com/facebook/buck/raw/027ffe2b230c08cad7b340646c6f801bd6dabc78/third-party/java/infer-annotations/infer-annotations-1.4.jar
+
+java: transpile_all src/java | $(JAVA_LIB_DIR)/junit4.jar $(JAVA_LIB_DIR)/jsr305.jar $(JAVA_LIB_DIR)/infer-annotations-1.4.jar
+	@javac -cp ./$(JAVA_LIB_DIR)/junit4.jar$(ENVSEP)./$(JAVA_LIB_DIR)/jsr305.jar$(ENVSEP)./$(JAVA_LIB_DIR)/infer-annotations-1.4.jar -sourcepath ./src/java/src$(ENVSEP)./src/java/tests src/java/tests/com/facebook/csslayout/*.java
 
 java_test: java
-	@java -cp ./src/java/src:./src/java/tests:./lib/junit4.jar:./lib/infer-annotations-1.4.jar org.junit.runner.JUnitCore \
+	@java -cp ./src/java/src$(ENVSEP)./src/java/tests$(ENVSEP)./$(JAVA_LIB_DIR)/junit4.jar$(ENVSEP)./$(JAVA_LIB_DIR)/infer-annotations-1.4.jar org.junit.runner.JUnitCore \
       com.facebook.csslayout.LayoutEngineTest \
       com.facebook.csslayout.LayoutCachingTest \
       com.facebook.csslayout.CSSNodeTest
@@ -31,5 +53,5 @@ transpile_all: ./src/transpile.js
 	@node ./src/transpile.js
 
 debug:
-	@gcc -ggdb $(FILES) -lm && lldb ./a.out
-	@rm a.out
+	@gcc -std=c99 -ggdb $(FILES) -lm -o $(C_TEST_EXE) && $(LLDB) $(C_TEST_EXE)
+	@rm $(C_TEST_EXE)