diff --git a/bsputil/bsputil.c b/bsputil/bsputil.c
index c8877329..69529cdc 100644
--- a/bsputil/bsputil.c
+++ b/bsputil/bsputil.c
@@ -111,7 +111,7 @@ PrintModelInfo(const bspdata_t *bsp)
  * Quick hack to check verticies of faces lie on the correct plane
  */
 #define ON_EPSILON 0.01
-vec3_t vec3_origin = { 0, 0, 0 };
+const vec3_t vec3_origin = { 0, 0, 0 };
 static void
 CheckBSPFacesPlanar(const bspdata_t *bsp)
 {
diff --git a/common/mathlib.c b/common/mathlib.c
index 1accdc54..c7dadbf5 100644
--- a/common/mathlib.c
+++ b/common/mathlib.c
@@ -20,7 +20,7 @@
 #include <common/cmdlib.h>
 #include <common/mathlib.h>
 
-vec3_t vec3_origin = { 0, 0, 0 };
+const vec3_t vec3_origin = { 0, 0, 0 };
 
 
 double
diff --git a/include/common/mathlib.h b/include/common/mathlib.h
index b41e1687..19cdfe33 100644
--- a/include/common/mathlib.h
+++ b/include/common/mathlib.h
@@ -39,7 +39,7 @@ typedef vec_t vec3_t[3];
 
 #define Q_PI 3.14159265358979323846
 
-extern vec3_t vec3_origin;
+extern const vec3_t vec3_origin;
 
 #define EQUAL_EPSILON 0.001
 
diff --git a/qbsp/globals.c b/qbsp/globals.c
index 3bfd77c0..62f2406d 100644
--- a/qbsp/globals.c
+++ b/qbsp/globals.c
@@ -97,7 +97,7 @@ mapdata_t map;
 mapentity_t *pWorldEnt;
 
 // Mathlib.c
-vec3_t vec3_origin = { 0, 0, 0 };
+const vec3_t vec3_origin = { 0, 0, 0 };
 
 // util.c
 FILE *logfile;
diff --git a/qbsp/qbsp.h b/qbsp/qbsp.h
index c2ebaeed..7c73d5cd 100644
--- a/qbsp/qbsp.h
+++ b/qbsp/qbsp.h
@@ -187,7 +187,7 @@ typedef float vec_t;
 #endif
 typedef vec_t vec3_t[3];
 
-extern vec3_t vec3_origin;
+extern const vec3_t vec3_origin;
 
 bool VectorCompare(const vec3_t v1, const vec3_t v2);