diff --git a/Makefile b/Makefile
index 6771022c..d10dbf2c 100644
--- a/Makefile
+++ b/Makefile
@@ -18,15 +18,15 @@ all: _sass.so
 
 build2/libsass/c/%.o: libsass/src/%.c
 	@mkdir -p build2/libsass/c/
-	gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I./libsass/include $(PY_HEADERS) -c $^ -o $@ -c -O2 -fPIC -std=c++0x -Wall -Wno-parentheses
+	gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I./libsass/include $(PY_HEADERS) -c $^ -o $@ -c -O2 -fPIC -std=c++0x -Wall -Wno-parentheses -Werror=switch
 
 build2/libsass/cpp/%.o: libsass/src/%.cpp
 	@mkdir -p build2/libsass/cpp/
-	gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I./libsass/include $(PY_HEADERS) -c $^ -o $@ -c -O2 -fPIC -std=c++0x -Wall -Wno-parentheses
+	gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I./libsass/include $(PY_HEADERS) -c $^ -o $@ -c -O2 -fPIC -std=c++0x -Wall -Wno-parentheses -Werror=switch
 
 build2/pysass.o: pysass.cpp
 	@mkdir -p build2
-	gcc -pthread -fno-strict-aliasing -Wno-write-strings -DNDEBUG -g -fwrapv -O2 -Wall -fPIC -I./libsass/include $(PY_HEADERS) -c $^ -o $@ -c -O2 -fPIC -std=c++0x -Wall -Wno-parentheses
+	gcc -pthread -fno-strict-aliasing -Wno-write-strings -DNDEBUG -g -fwrapv -O2 -Wall -fPIC -I./libsass/include $(PY_HEADERS) -c $^ -o $@ -c -O2 -fPIC -std=c++0x -Wall -Wno-parentheses -Werror=switch
 
 _sass.so: $(C_OBJECTS) $(CPP_OBJECTS) build2/pysass.o
 	g++ -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro $^ -L./libsass -o $@ -fPIC -lstdc++
diff --git a/pysass.cpp b/pysass.cpp
index 7ecdde3a..d486da09 100644
--- a/pysass.cpp
+++ b/pysass.cpp
@@ -84,6 +84,9 @@ static PyObject* _to_py_value(const union Sass_Value* value) {
                 case SASS_SPACE:
                     separator = sass_space;
                     break;
+                case SASS_HASH:
+                    assert(0);
+                    break;
             }
             for (i = 0; i < sass_list_get_length(value); i += 1) {
                 PyTuple_SetItem(
diff --git a/setup.py b/setup.py
index e3df3f18..d70dffd6 100644
--- a/setup.py
+++ b/setup.py
@@ -73,7 +73,9 @@ def spawn(self, cmd):
     flags = ['-c', '-O2', '/EHsc', '/MT']
     link_flags = []
 else:
-    flags = ['-fPIC', '-std=c++0x', '-Wall', '-Wno-parentheses']
+    flags = [
+        '-fPIC', '-std=c++0x', '-Wall', '-Wno-parentheses', '-Werror=switch',
+    ]
     platform.mac_ver()
     if platform.system() in ['Darwin', 'FreeBSD']:
         os.environ.setdefault('CC', 'clang')