diff --git a/src/galaxy/mission.c b/src/galaxy/mission.c
index d284feb..6ebb636 100644
--- a/src/galaxy/mission.c
+++ b/src/galaxy/mission.c
@@ -201,7 +201,7 @@ void loadMission(char *filename)
 
 static char *getAutoBackground(char *filename)
 {
-	int hash;
+	unsigned long hash;
 
 	if (!game.currentMission->challengeData.isChallenge)
 	{
@@ -217,7 +217,7 @@ static char *getAutoBackground(char *filename)
 
 static char *getAutoPlanet(char *filename)
 {
-	int hash;
+	unsigned long hash;
 
 	if (!game.currentMission->challengeData.isChallenge)
 	{
@@ -233,7 +233,7 @@ static char *getAutoPlanet(char *filename)
 
 static char *getAutoMusic(char *filename)
 {
-	int hash;
+	unsigned long hash;
 
 	if (!game.currentMission->challengeData.isChallenge)
 	{
@@ -241,7 +241,7 @@ static char *getAutoMusic(char *filename)
 	}
 	else
 	{
-		hash = hashcode(filename);
+		hash = hashcode(game.currentMission->description);
 	}
 
 	return getMusicFilename(hash);
diff --git a/src/galaxy/mission.h b/src/galaxy/mission.h
index c616bdd..2329592 100644
--- a/src/galaxy/mission.h
+++ b/src/galaxy/mission.h
@@ -44,9 +44,9 @@ extern void initMissionInfo(void);
 extern char *getTranslatedString(char *string);
 extern void updateStarSystemMissions(void);
 extern void updateChallengeMissions(void);
-extern char *getBackgroundTextureName(int n);
-extern char *getPlanetTextureName(int n);
-extern char *getMusicFilename(int n);
+extern char *getBackgroundTextureName(unsigned long n);
+extern char *getPlanetTextureName(unsigned long n);
+extern char *getMusicFilename(unsigned long n);
 extern int getJSONValue(cJSON *node, char *name, int defValue);
 extern char *getJSONValueStr(cJSON *node, char *name, char *defValue);
 extern void addAllToQuadtree(void);
diff --git a/src/system/resources.c b/src/system/resources.c
index ba88d56..34f6b63 100644
--- a/src/system/resources.c
+++ b/src/system/resources.c
@@ -81,17 +81,17 @@ void initResources(void)
 	free(filenames);
 }
 
-char *getBackgroundTextureName(int i)
+char *getBackgroundTextureName(unsigned long i)
 {
 	return backgrounds[i % numBackgrounds];
 }
 
-char *getPlanetTextureName(int i)
+char *getPlanetTextureName(unsigned long i)
 {
 	return planets[i % numPlanets];
 }
 
-char *getMusicFilename(int i)
+char *getMusicFilename(unsigned long i)
 {
 	return musicFiles[i % numMusicFiles];
 }