diff --git a/src/avp/bh_ais.c b/src/avp/bh_ais.c
index 6e5f55e..3c789f2 100644
--- a/src/avp/bh_ais.c
+++ b/src/avp/bh_ais.c
@@ -731,7 +731,7 @@ int NPCSetVelocity(STRATEGYBLOCK *sbPtr, VECTORCH* targetDirn, int in_speed)
         } else {
                 int accelerationThisFrame,deltaVMag,dotProduct;
                 VECTORCH deltaV,targetV,yDirection,movementOffset;
-                MOVEMENT_DATA *movementData;
+                const MOVEMENT_DATA *movementData;
 
                 /* Mode 2, for marines 'n' predators.  And xenoborgs. */
                 
diff --git a/src/avp/bh_ais.h b/src/avp/bh_ais.h
index da35472..81707ba 100644
--- a/src/avp/bh_ais.h
+++ b/src/avp/bh_ais.h
@@ -209,7 +209,7 @@ extern int New_NPC_IsObstructed(STRATEGYBLOCK *sbPtr, NPC_AVOIDANCEMANAGER *mana
 extern void Initialise_AvoidanceManager(STRATEGYBLOCK *sbPtr, NPC_AVOIDANCEMANAGER *manager);
 extern AVOIDANCE_RETURN_CONDITION AllNewAvoidanceKernel(STRATEGYBLOCK *sbPtr,NPC_AVOIDANCEMANAGER *manager);
 /* All New Avoidance Code! */
-extern MOVEMENT_DATA *GetThisMovementData(MOVEMENT_DATA_INDEX index);
+extern const MOVEMENT_DATA *GetThisMovementData(MOVEMENT_DATA_INDEX index);
 extern void AlignVelocityToGravity(STRATEGYBLOCK *sbPtr,VECTORCH *velocity);
 
 extern int NPC_targetIsPlayer; 
diff --git a/src/avp/bh_marin.c b/src/avp/bh_marin.c
index 3ca31ce..71c85e8 100644
--- a/src/avp/bh_marin.c
+++ b/src/avp/bh_marin.c
@@ -1436,7 +1436,7 @@ void CreateMarineBot(VECTORCH *Position, int weapon)
 		}
 		
 		{
-			MOVEMENT_DATA *movementData;
+			const MOVEMENT_DATA *movementData;
 
 			marineStatus->speedConstant=(ONE_FIXED-8192)+(FastRandom()&16383);
 			marineStatus->accelerationConstant=(ONE_FIXED-8192)+(FastRandom()&16383);
@@ -1734,7 +1734,7 @@ void InitMarineBehaviour(void* bhdata, STRATEGYBLOCK *sbPtr)
 		marineStatus->roundsForThisTarget=0;
 
 		{
-			MOVEMENT_DATA *movementData;
+			const MOVEMENT_DATA *movementData;
 
 			marineStatus->speedConstant=(ONE_FIXED-8192)+(FastRandom()&16383);
 			marineStatus->accelerationConstant=(ONE_FIXED-8192)+(FastRandom()&16383);
@@ -2058,7 +2058,7 @@ void CreateMarineDynamic(STRATEGYBLOCK *Generator,MARINE_NPC_WEAPONS weapon_for_
 		}
 		
 		{
-			MOVEMENT_DATA *movementData;
+			const MOVEMENT_DATA *movementData;
 
 			marineStatus->speedConstant=(ONE_FIXED-8192)+(FastRandom()&16383);
 			marineStatus->accelerationConstant=(ONE_FIXED-8192)+(FastRandom()&16383);
@@ -8728,7 +8728,7 @@ static void HandleMovingAnimations(STRATEGYBLOCK *sbPtr) {
 	MARINE_STATUS_BLOCK *marineStatusPointer;    
 	MARINE_MOVEMENT_STYLE style;
 	MARINE_BHSTATE baseState;
-	MOVEMENT_DATA *movementData;
+	const MOVEMENT_DATA *movementData;
 	VECTORCH offset;
 	int can_mooch_bored;
 	int can_mooch_alert;
diff --git a/src/avp/movement.c b/src/avp/movement.c
index 5f342da..579cd58 100644
--- a/src/avp/movement.c
+++ b/src/avp/movement.c
@@ -38,7 +38,7 @@
 /* Individual marines vary this by +/- 12.5%. */
 /* Predators and xenoborgs don't at the moment. */
 
-static MOVEMENT_DATA Movement_Stats[] = {
+static const MOVEMENT_DATA Movement_Stats[] = {
 	{
 		MDI_Marine_Mooch_Bored,
 		1500,
@@ -101,7 +101,7 @@ static MOVEMENT_DATA Movement_Stats[] = {
 	},
 };
 
-MOVEMENT_DATA *GetThisMovementData(MOVEMENT_DATA_INDEX index) {
+const MOVEMENT_DATA *GetThisMovementData(MOVEMENT_DATA_INDEX index) {
 	
 	int a;