diff --git a/src/environment.cpp b/src/environment.cpp
index 906f35219..c997be3ff 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -83,6 +83,24 @@ float Environment::getTimeOfDayF()
 	return m_time_of_day_f;
 }
 
+bool Environment::line_of_sight(v3f pos1, v3f pos2, v3s16 *p)
+{
+	// Iterate trough nodes on the line
+	voxalgo::VoxelLineIterator iterator(pos1 / BS, (pos2 - pos1) / BS);
+	do {
+		MapNode n = getMap().getNode(iterator.m_current_node_pos);
+
+		// Return non-air
+		if (n.param0 != CONTENT_AIR) {
+			if (p)
+				*p = iterator.m_current_node_pos;
+			return false;
+		}
+		iterator.next();
+	} while (iterator.m_current_index <= iterator.m_last_index);
+	return true;
+}
+
 /*
 	Check if a node is pointable
 */
diff --git a/src/environment.h b/src/environment.h
index f568ba228..91c33ba15 100644
--- a/src/environment.h
+++ b/src/environment.h
@@ -76,6 +76,16 @@ public:
 
 	u32 getDayCount();
 
+	/*!
+	 * Returns false if the given line intersects with a
+	 * non-air node, true otherwise.
+	 * \param pos1 start of the line
+	 * \param pos2 end of the line
+	 * \param p output, position of the first non-air node
+	 * the line intersects
+	 */
+	bool line_of_sight(v3f pos1, v3f pos2, v3s16 *p = nullptr);
+
 	/*!
 	 * Gets the objects pointed by the shootline as
 	 * pointed things.
diff --git a/src/script/lua_api/l_env.cpp b/src/script/lua_api/l_env.cpp
index 3169fa4cf..31e582d3d 100644
--- a/src/script/lua_api/l_env.cpp
+++ b/src/script/lua_api/l_env.cpp
@@ -139,8 +139,7 @@ void LuaLBM::trigger(ServerEnvironment *env, v3s16 p, MapNode n)
 
 int LuaRaycast::l_next(lua_State *L)
 {
-	MAP_LOCK_REQUIRED;
-	GET_ENV_PTR;
+	GET_PLAIN_ENV_PTR;
 
 	bool csm = false;
 #ifndef SERVER
@@ -384,7 +383,7 @@ int ModApiEnvMod::l_get_node_or_nil(lua_State *L)
 // timeofday: nil = current time, 0 = night, 0.5 = day
 int ModApiEnvMod::l_get_node_light(lua_State *L)
 {
-	GET_ENV_PTR;
+	GET_PLAIN_ENV_PTR;
 
 	// Do it
 	v3s16 pos = read_v3s16(L, 1);
@@ -488,10 +487,7 @@ int ModApiEnvMod::l_punch_node(lua_State *L)
 // pos = {x=num, y=num, z=num}
 int ModApiEnvMod::l_get_node_max_level(lua_State *L)
 {
-	Environment *env = getEnv(L);
-	if (!env) {
-		return 0;
-	}
+	GET_PLAIN_ENV_PTR;
 
 	v3s16 pos = read_v3s16(L, 1);
 	MapNode n = env->getMap().getNode(pos);
@@ -503,10 +499,7 @@ int ModApiEnvMod::l_get_node_max_level(lua_State *L)
 // pos = {x=num, y=num, z=num}
 int ModApiEnvMod::l_get_node_level(lua_State *L)
 {
-	Environment *env = getEnv(L);
-	if (!env) {
-		return 0;
-	}
+	GET_PLAIN_ENV_PTR;
 
 	v3s16 pos = read_v3s16(L, 1);
 	MapNode n = env->getMap().getNode(pos);
@@ -551,7 +544,7 @@ int ModApiEnvMod::l_add_node_level(lua_State *L)
 // find_nodes_with_meta(pos1, pos2)
 int ModApiEnvMod::l_find_nodes_with_meta(lua_State *L)
 {
-	GET_ENV_PTR;
+	GET_PLAIN_ENV_PTR;
 
 	std::vector<v3s16> positions = env->getMap().findNodesWithMetadata(
 		check_v3s16(L, 1), check_v3s16(L, 2));
@@ -728,10 +721,7 @@ int ModApiEnvMod::l_set_timeofday(lua_State *L)
 // get_timeofday() -> 0...1
 int ModApiEnvMod::l_get_timeofday(lua_State *L)
 {
-	Environment *env = getEnv(L);
-	if (!env) {
-		return 0;
-	}
+	GET_PLAIN_ENV_PTR;
 
 	// Do it
 	int timeofday_mh = env->getTimeOfDay();
@@ -743,10 +733,7 @@ int ModApiEnvMod::l_get_timeofday(lua_State *L)
 // get_day_count() -> int
 int ModApiEnvMod::l_get_day_count(lua_State *L)
 {
-	Environment *env = getEnv(L);
-	if (!env) {
-		return 0;
-	}
+	GET_PLAIN_ENV_PTR;
 
 	lua_pushnumber(L, env->getDayCount());
 	return 1;
@@ -767,12 +754,9 @@ int ModApiEnvMod::l_get_gametime(lua_State *L)
 // nodenames: eg. {"ignore", "group:tree"} or "default:dirt"
 int ModApiEnvMod::l_find_node_near(lua_State *L)
 {
-	Environment *env = getEnv(L);
-	if (!env) {
-		return 0;
-	}
+	GET_PLAIN_ENV_PTR;
 
-	const NodeDefManager *ndef = getGameDef(L)->ndef();
+	const NodeDefManager *ndef = env->getGameDef()->ndef();
 	v3s16 pos = read_v3s16(L, 1);
 	int radius = luaL_checkinteger(L, 2);
 	std::vector<content_t> filter;
@@ -815,20 +799,19 @@ int ModApiEnvMod::l_find_node_near(lua_State *L)
 // nodenames: eg. {"ignore", "group:tree"} or "default:dirt"
 int ModApiEnvMod::l_find_nodes_in_area(lua_State *L)
 {
-	GET_ENV_PTR;
+	GET_PLAIN_ENV_PTR;
 
 	v3s16 minp = read_v3s16(L, 1);
 	v3s16 maxp = read_v3s16(L, 2);
 	sortBoxVerticies(minp, maxp);
 
+	const NodeDefManager *ndef = env->getGameDef()->ndef();
+
 #ifndef SERVER
-	const NodeDefManager *ndef = getClient(L) ? getClient(L)->ndef() : getServer(L)->ndef();
 	if (getClient(L)) {
 		minp = getClient(L)->CSMClampPos(minp);
 		maxp = getClient(L)->CSMClampPos(maxp);
 	}
-#else
-	const NodeDefManager *ndef = getServer(L)->ndef();
 #endif
 
 	v3s16 cube = maxp - minp + 1;
@@ -892,20 +875,19 @@ int ModApiEnvMod::l_find_nodes_in_area_under_air(lua_State *L)
 	 * TODO
 	 */
 
-	GET_ENV_PTR;
+	GET_PLAIN_ENV_PTR;
 
 	v3s16 minp = read_v3s16(L, 1);
 	v3s16 maxp = read_v3s16(L, 2);
 	sortBoxVerticies(minp, maxp);
 
+	const NodeDefManager *ndef = env->getGameDef()->ndef();
+
 #ifndef SERVER
-	const NodeDefManager *ndef = getClient(L) ? getClient(L)->ndef() : getServer(L)->ndef();
 	if (getClient(L)) {
 		minp = getClient(L)->CSMClampPos(minp);
 		maxp = getClient(L)->CSMClampPos(maxp);
 	}
-#else
-	const NodeDefManager *ndef = getServer(L)->ndef();
 #endif
 
 	v3s16 cube = maxp - minp + 1;
@@ -1034,7 +1016,7 @@ int ModApiEnvMod::l_clear_objects(lua_State *L)
 // line_of_sight(pos1, pos2) -> true/false, pos
 int ModApiEnvMod::l_line_of_sight(lua_State *L)
 {
-	GET_ENV_PTR;
+	GET_PLAIN_ENV_PTR;
 
 	// read position 1 from lua
 	v3f pos1 = checkFloatPos(L, 1);
diff --git a/src/script/lua_api/l_internal.h b/src/script/lua_api/l_internal.h
index bbedfe46e..a86eeaf79 100644
--- a/src/script/lua_api/l_internal.h
+++ b/src/script/lua_api/l_internal.h
@@ -32,14 +32,39 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define luamethod_aliased(class, name, alias) {#name, class::l_##name}, {#alias, class::l_##name}
 #define API_FCT(name) registerFunction(L, #name, l_##name, top)
 
-#define MAP_LOCK_REQUIRED
-#define NO_MAP_LOCK_REQUIRED
+// For future use
+#define MAP_LOCK_REQUIRED ((void)0)
+#define NO_MAP_LOCK_REQUIRED ((void)0)
 
+/* In debug mode ensure no code tries to retrieve the server env when it isn't
+ * actually available (in CSM) */
+#if !defined(SERVER) && !defined(NDEBUG)
+#define DEBUG_ASSERT_NO_CLIENTAPI                    \
+	FATAL_ERROR_IF(getClient(L) != nullptr, "Tried " \
+		"to retrieve ServerEnvironment on client")
+#else
+#define DEBUG_ASSERT_NO_CLIENTAPI ((void)0)
+#endif
+
+// Retrieve ServerEnvironment pointer as `env` (no map lock)
 #define GET_ENV_PTR_NO_MAP_LOCK                              \
+	DEBUG_ASSERT_NO_CLIENTAPI;                               \
 	ServerEnvironment *env = (ServerEnvironment *)getEnv(L); \
 	if (env == NULL)                                         \
 		return 0
 
+// Retrieve ServerEnvironment pointer as `env`
 #define GET_ENV_PTR         \
 	MAP_LOCK_REQUIRED;      \
 	GET_ENV_PTR_NO_MAP_LOCK
+
+// Retrieve Environment pointer as `env` (no map lock)
+#define GET_PLAIN_ENV_PTR_NO_MAP_LOCK            \
+	Environment *env = (Environment *)getEnv(L); \
+	if (env == NULL)                             \
+		return 0
+
+// Retrieve Environment pointer as `env`
+#define GET_PLAIN_ENV_PTR         \
+	MAP_LOCK_REQUIRED;            \
+	GET_PLAIN_ENV_PTR_NO_MAP_LOCK
diff --git a/src/script/lua_api/l_object.cpp b/src/script/lua_api/l_object.cpp
index 23ed1ffe0..5cd978d73 100644
--- a/src/script/lua_api/l_object.cpp
+++ b/src/script/lua_api/l_object.cpp
@@ -533,7 +533,7 @@ int ObjectRef::l_set_local_animation(lua_State *L)
 // get_local_animation(self)
 int ObjectRef::l_get_local_animation(lua_State *L)
 {
-	NO_MAP_LOCK_REQUIRED
+	NO_MAP_LOCK_REQUIRED;
 	ObjectRef *ref = checkobject(L, 1);
 	RemotePlayer *player = getplayer(ref);
 	if (player == NULL)
diff --git a/src/serverenvironment.cpp b/src/serverenvironment.cpp
index 2d3ee078e..0ccbd772b 100644
--- a/src/serverenvironment.cpp
+++ b/src/serverenvironment.cpp
@@ -545,24 +545,6 @@ bool ServerEnvironment::removePlayerFromDatabase(const std::string &name)
 	return m_player_database->removePlayer(name);
 }
 
-bool ServerEnvironment::line_of_sight(v3f pos1, v3f pos2, v3s16 *p)
-{
-	// Iterate trough nodes on the line
-	voxalgo::VoxelLineIterator iterator(pos1 / BS, (pos2 - pos1) / BS);
-	do {
-		MapNode n = getMap().getNode(iterator.m_current_node_pos);
-
-		// Return non-air
-		if (n.param0 != CONTENT_AIR) {
-			if (p)
-				*p = iterator.m_current_node_pos;
-			return false;
-		}
-		iterator.next();
-	} while (iterator.m_current_index <= iterator.m_last_index);
-	return true;
-}
-
 void ServerEnvironment::kickAllPlayers(AccessDeniedCode reason,
 	const std::string &str_reason, bool reconnect)
 {
diff --git a/src/serverenvironment.h b/src/serverenvironment.h
index 3c7b7d059..bf10e3ca8 100644
--- a/src/serverenvironment.h
+++ b/src/serverenvironment.h
@@ -334,16 +334,6 @@ public:
 	// This makes stuff happen
 	void step(f32 dtime);
 
-	/*!
-	 * Returns false if the given line intersects with a
-	 * non-air node, true otherwise.
-	 * \param pos1 start of the line
-	 * \param pos2 end of the line
-	 * \param p output, position of the first non-air node
-	 * the line intersects
-	 */
-	bool line_of_sight(v3f pos1, v3f pos2, v3s16 *p = NULL);
-
 	u32 getGameTime() const { return m_game_time; }
 
 	void reportMaxLagEstimate(float f) { m_max_lag_estimate = f; }