diff --git a/src/client/hud.cpp b/src/client/hud.cpp
index 5137c2f3e..fffe85e1d 100644
--- a/src/client/hud.cpp
+++ b/src/client/hud.cpp
@@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 
 #include "client/hud.h"
+#include <cmath>
 #include "settings.h"
 #include "util/numeric.h"
 #include "log.h"
@@ -50,7 +51,7 @@ Hud::Hud(gui::IGUIEnvironment *guienv, Client *client, LocalPlayer *player,
 	this->inventory   = inventory;
 
 	m_hud_scaling      = g_settings->getFloat("hud_scaling");
-	m_hotbar_imagesize = floor(HOTBAR_IMAGE_SIZE *
+	m_hotbar_imagesize = std::floor(HOTBAR_IMAGE_SIZE *
 		RenderingEngine::getDisplayDensity() + 0.5f);
 	m_hotbar_imagesize *= m_hud_scaling;
 	m_padding = m_hotbar_imagesize / 12;
@@ -336,7 +337,8 @@ void Hud::drawLuaElements(const v3s16 &camera_offset)
 			case HUD_ELEM_WAYPOINT: {
 				v3f p_pos = player->getPosition() / BS;
 				v3f w_pos = e->world_pos * BS;
-				float distance = floor(10 * p_pos.getDistanceFrom(e->world_pos)) / 10;
+				float distance = std::floor(10 * p_pos.getDistanceFrom(e->world_pos)) /
+					10.0f;
 				scene::ICameraSceneNode* camera =
 					RenderingEngine::get_scene_manager()->getActiveCamera();
 				w_pos -= intToFloat(camera_offset, BS);
@@ -735,12 +737,12 @@ void drawItemStack(video::IVideoDriver *driver,
 		//   wear = 0.5: yellow
 		//   wear = 1.0: red
 		video::SColor color(255,255,255,255);
-		int wear_i = MYMIN(floor(wear * 600), 511);
+		int wear_i = MYMIN(std::floor(wear * 600), 511);
 		wear_i = MYMIN(wear_i + 10, 511);
-		if(wear_i <= 255)
+		if (wear_i <= 255)
 			color.set(255, wear_i, 255, 0);
 		else
-			color.set(255, 255, 511-wear_i, 0);
+			color.set(255, 255, 511 - wear_i, 0);
 
 		core::rect<s32> progressrect2 = progressrect;
 		progressrect2.LowerRightCorner.X = progressmid;
diff --git a/src/hud.cpp b/src/hud.cpp
index 0d2d092a7..e4a20190d 100644
--- a/src/hud.cpp
+++ b/src/hud.cpp
@@ -1,5 +1,24 @@
-#include "hud.h"
+/*
+Minetest
+Copyright (C) 2010-2018 celeron55, Perttu Ahola <celeron55@gmail.com>
 
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "hud.h"
+#include <cmath>
 
 const struct EnumString es_HudElementType[] =
 {
diff --git a/src/script/lua_api/l_camera.cpp b/src/script/lua_api/l_camera.cpp
index 49622df00..326cc6d53 100644
--- a/src/script/lua_api/l_camera.cpp
+++ b/src/script/lua_api/l_camera.cpp
@@ -1,5 +1,25 @@
-#include "script/common/c_converter.h"
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
 #include "l_camera.h"
+#include <cmath>
+#include "script/common/c_converter.h"
 #include "l_internal.h"
 #include "content_cao.h"
 #include "camera.h"
@@ -98,7 +118,8 @@ int LuaCamera::l_get_look_dir(lua_State *L)
 
 	float pitch = -1.0 * player->getPitch() * core::DEGTORAD;
 	float yaw = (player->getYaw() + 90.) * core::DEGTORAD;
-	v3f v(cos(pitch) * cos(yaw), sin(pitch), cos(pitch) * sin(yaw));
+	v3f v(std::cos(pitch) * std::cos(yaw), std::sin(pitch),
+			std::cos(pitch) * std::sin(yaw));
 
 	push_v3f(L, v);
 	return 1;
diff --git a/src/util/numeric.cpp b/src/util/numeric.cpp
index cb984d8cb..b88b4d545 100644
--- a/src/util/numeric.cpp
+++ b/src/util/numeric.cpp
@@ -157,7 +157,7 @@ bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
 	// HOTFIX: use sligthly increased angle (+10%) to fix too agressive
 	// culling. Somebody have to find out whats wrong with the math here.
 	// Previous value: camera_fov / 2
-	if(cosangle < cos(camera_fov * 0.55))
+	if (cosangle < std::cos(camera_fov * 0.55f))
 		return false;
 
 	return true;
@@ -172,6 +172,6 @@ s16 adjustDist(s16 dist, float zoom_fov)
 		return dist;
 
 	// new_dist = dist * ((1 - cos(FOV / 2)) / (1-cos(zoomFOV /2))) ^ (1/3)
-	return round(dist * cbrt((1.0f - std::cos(default_fov / 2.0f)) /
+	return round(dist * std::cbrt((1.0f - std::cos(default_fov / 2.0f)) /
 		(1.0f - std::cos(zoom_fov / 2.0f))));
 }