diff --git a/vm/primitives.cpp b/vm/primitives.cpp
index 8fb8afaa6a..08db684ff6 100755
--- a/vm/primitives.cpp
+++ b/vm/primitives.cpp
@@ -3,7 +3,7 @@
 namespace factor
 {
 
-primitive_type primitives[] = {
+const primitive_type primitives[] = {
 	primitive_bignum_to_fixnum,
 	primitive_float_to_fixnum,
 	primitive_fixnum_to_bignum,
diff --git a/vm/primitives.hpp b/vm/primitives.hpp
index bc692745dd..c520a67cc5 100644
--- a/vm/primitives.hpp
+++ b/vm/primitives.hpp
@@ -2,7 +2,7 @@ namespace factor
 {
 
 extern "C" typedef void (*primitive_type)();
-extern primitive_type primitives[];
+extern const primitive_type primitives[];
 
 #define PRIMITIVE(name) extern "C" void primitive_##name()