diff --git a/Cargo.toml b/Cargo.toml
index f16bed168..2a11129c0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,9 @@ authors = ["The Servo Project Developers"]
 
 build = "make -f makefile.cargo"
 
+[features]
+debugmozjs = ['mozjs-sys/debugmozjs']
+
 [dependencies.mozjs-sys]
 
 git = "https://github.com/servo/mozjs"
diff --git a/makefile.cargo b/makefile.cargo
index ed3d569f0..4de403688 100644
--- a/makefile.cargo
+++ b/makefile.cargo
@@ -10,12 +10,16 @@ AR ?= ar
 
 endif
 
-CFLAGS += -fPIC
+CFLAGS += -fPIC -DJS_NO_JSVAL_JSID_STRUCT_TYPES
 
 ifeq ($(shell $(CXX) -v 2>&1 | grep -c 'clang version\|Apple.*clang'),1)
 CFLAGS += -Wno-c++0x-extensions -Wno-return-type-c-linkage -Wno-invalid-offsetof
 endif
 
+ifneq (,$(CARGO_FEATURE_DEBUGMOZJS))
+	CFLAGS += -g -O0 -DDEBUG -D_DEBUG
+endif
+
 MOZJS_OUTDIR = $(shell find $(OUT_DIR)/.. -name 'mozjs-sys-*' -type d)
 CFLAGS += -I$(MOZJS_OUTDIR)/dist/include
 
diff --git a/src/lib.rs b/src/lib.rs
index 334524992..7340062ff 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,7 +7,7 @@
 
 #![feature(globs, link_args, managed_boxes, phase, unsafe_destructor)]
 
-#![allow(non_uppercase_statics, non_camel_case_types, non_snake_case_functions)]
+#![allow(non_uppercase_statics, non_camel_case_types, non_snake_case, ctypes)]
 
 #![reexport_test_harness_main = "test_main"]