diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..a7c365c
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "cJSON"]
+	path = cJSON
+	url = https://github.com/DaveGamble/cJSON
diff --git a/Makefile b/Makefile
index a30652e..c77e90f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,11 @@
-CC = clang
-CFLAGS = -O2
+CC = gcc
+CFLAGS = -O3
 LIBS = -lcjson
 
 all: make-libs-string
 
 make-libs-string:
-	$(CC) $(CFLAGS) make-libs-string.c $(LIBS) -o $@
+	$(CC) $(CFLAGS) -o $@ make-libs-string.c $(LIBS)
 
 clean:
 	rm make-libs-string
diff --git a/cJSON b/cJSON
new file mode 160000
index 0000000..cb8693b
--- /dev/null
+++ b/cJSON
@@ -0,0 +1 @@
+Subproject commit cb8693b058ba302f4829ec6d03f609ac6f848546