diff --git a/shaders/blend_amap_alpha.f.glsl b/shaders/blend_amap_alpha.f.glsl
index 6adb70b..1f46f9d 100644
--- a/shaders/blend_amap_alpha.f.glsl
+++ b/shaders/blend_amap_alpha.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float threshold;
 
diff --git a/shaders/blend_amap_color.f.glsl b/shaders/blend_amap_color.f.glsl
index c1c4353..5250bf6 100644
--- a/shaders/blend_amap_color.f.glsl
+++ b/shaders/blend_amap_color.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform vec4 color;
 
diff --git a/shaders/copy.f.glsl b/shaders/copy.f.glsl
index 6363711..46c53c3 100644
--- a/shaders/copy.f.glsl
+++ b/shaders/copy.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 
 in vec2 tex_coord;
diff --git a/shaders/copy_alpha_key.f.glsl b/shaders/copy_alpha_key.f.glsl
index 2aaeaeb..03c3a12 100644
--- a/shaders/copy_alpha_key.f.glsl
+++ b/shaders/copy_alpha_key.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform vec4 color;
 
diff --git a/shaders/copy_color_reverse.f.glsl b/shaders/copy_color_reverse.f.glsl
index 4160336..7a491af 100644
--- a/shaders/copy_color_reverse.f.glsl
+++ b/shaders/copy_color_reverse.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 
 in vec2 tex_coord;
diff --git a/shaders/copy_key.f.glsl b/shaders/copy_key.f.glsl
index 4ab69e4..3c33ff0 100644
--- a/shaders/copy_key.f.glsl
+++ b/shaders/copy_key.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform vec4 color;
 
diff --git a/shaders/copy_use_amap_border.f.glsl b/shaders/copy_use_amap_border.f.glsl
index ef1f4da..f11ba31 100644
--- a/shaders/copy_use_amap_border.f.glsl
+++ b/shaders/copy_use_amap_border.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float threshold;
 
diff --git a/shaders/copy_use_amap_under.f.glsl b/shaders/copy_use_amap_under.f.glsl
index 342713c..3a57319 100644
--- a/shaders/copy_use_amap_under.f.glsl
+++ b/shaders/copy_use_amap_under.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float threshold;
 
diff --git a/shaders/dungeon.f.glsl b/shaders/dungeon.f.glsl
index 0e7c456..cb60d00 100644
--- a/shaders/dungeon.f.glsl
+++ b/shaders/dungeon.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float alpha_mod;
 
diff --git a/shaders/dungeon.v.glsl b/shaders/dungeon.v.glsl
index 4cfe35f..4828602 100644
--- a/shaders/dungeon.v.glsl
+++ b/shaders/dungeon.v.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform mat4 local_transform;
 uniform mat4 view_transform;
 uniform mat4 proj_transform;
diff --git a/shaders/dungeon_skybox.f.glsl b/shaders/dungeon_skybox.f.glsl
index 2ef08a0..fdb1aab 100644
--- a/shaders/dungeon_skybox.f.glsl
+++ b/shaders/dungeon_skybox.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform samplerCube tex;
 
 in vec3 tex_coord;
diff --git a/shaders/dungeon_skybox.v.glsl b/shaders/dungeon_skybox.v.glsl
index 6f36502..18f7ea3 100644
--- a/shaders/dungeon_skybox.v.glsl
+++ b/shaders/dungeon_skybox.v.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform mat4 view_transform;
 uniform mat4 proj_transform;
 
diff --git a/shaders/fill.f.glsl b/shaders/fill.f.glsl
index 1dce654..27d5c84 100644
--- a/shaders/fill.f.glsl
+++ b/shaders/fill.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform vec4 color;
 
 in vec2 tex_coord;
diff --git a/shaders/fill_amap_over_border.f.glsl b/shaders/fill_amap_over_border.f.glsl
index 88b5310..a5f4835 100644
--- a/shaders/fill_amap_over_border.f.glsl
+++ b/shaders/fill_amap_over_border.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float threshold;
 uniform vec4 color;
diff --git a/shaders/fill_amap_under_border.f.glsl b/shaders/fill_amap_under_border.f.glsl
index 02406e8..df6839d 100644
--- a/shaders/fill_amap_under_border.f.glsl
+++ b/shaders/fill_amap_under_border.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float threshold;
 uniform vec4 color;
diff --git a/shaders/hitbox.f.glsl b/shaders/hitbox.f.glsl
index d0602b6..e1e3e4a 100644
--- a/shaders/hitbox.f.glsl
+++ b/shaders/hitbox.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform vec2 bot_left;
 uniform vec2 top_right;
@@ -29,11 +27,11 @@ float point_in_rect(vec2 p, vec2 bot_left, vec2 top_right) {
 }
 
 void main() {
-        ivec2 size = textureSize(tex, 0);
+        vec2 size = vec2(textureSize(tex, 0));
         vec2 tex_bot_left = bot_left / size;
         vec2 tex_top_right = top_right / size;
 
         vec4 texel = texture(tex, tex_coord);
         float t = point_in_rect(tex_coord, tex_bot_left, tex_top_right);
-        frag_color = t * texel + (1 - t) * vec4(0, 0, 0, 0);
+        frag_color = t * texel + (1.0 - t) * vec4(0, 0, 0, 0);
 }
diff --git a/shaders/hitbox_noblend.f.glsl b/shaders/hitbox_noblend.f.glsl
index 9c13e00..f935441 100644
--- a/shaders/hitbox_noblend.f.glsl
+++ b/shaders/hitbox_noblend.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform vec2 bot_left;
 uniform vec2 top_right;
@@ -29,12 +27,12 @@ float point_in_rect(vec2 p, vec2 bot_left, vec2 top_right) {
 }
 
 void main() {
-        ivec2 size = textureSize(tex, 0);
+        vec2 size = vec2(textureSize(tex, 0));
         vec2 tex_bot_left = bot_left / size;
         vec2 tex_top_right = top_right / size;
 
         vec4 texel = texture(tex, tex_coord);
-        texel.a = 1;
+        texel.a = 1.0;
         float t = point_in_rect(tex_coord, tex_bot_left, tex_top_right);
-        frag_color = t * texel + (1 - t) * vec4(0, 0, 0, 0);
+        frag_color = t * texel + (1.0 - t) * vec4(0, 0, 0, 0);
 }
diff --git a/shaders/render.f.glsl b/shaders/render.f.glsl
index d3f73ae..d7131e7 100644
--- a/shaders/render.f.glsl
+++ b/shaders/render.f.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform sampler2D tex;
 uniform float alpha_mod;
 
diff --git a/shaders/render.v.glsl b/shaders/render.v.glsl
index e76cec5..711a935 100644
--- a/shaders/render.v.glsl
+++ b/shaders/render.v.glsl
@@ -14,8 +14,6 @@
  * along with this program; if not, see <http://gnu.org/licenses/>.
  */
 
-#version 140
-
 uniform mat4 world_transform;
 uniform mat4 view_transform;
 
diff --git a/src/video.c b/src/video.c
index 0cd6644..da0e22c 100644
--- a/src/video.c
+++ b/src/video.c
@@ -32,6 +32,19 @@
 
 struct sdl_private sdl;
 
+/*
+ * Define this to target OpenGL ES 3.0.
+ */
+//#define USE_GLES
+
+static const GLchar glsl_preamble[] =
+#ifdef USE_GLES
+	"#version 300 es\n"
+	"precision highp float;\n";
+#else
+	"#version 140\n";
+#endif
+
 /*
  * Transform from the window coordinate system -> clip-space.
  *
@@ -84,16 +97,17 @@ static GLuint load_shader_file(const char *path, GLenum type)
 {
 	GLint shader_compiled;
 	GLuint shader;
-	const GLchar *source;
-
-	source = read_shader_file(path);
+	const GLchar *source[2] = {
+		glsl_preamble,
+		read_shader_file(path)
+	};
 	shader = glCreateShader(type);
-	glShaderSource(shader, 1, &source, NULL);
+	glShaderSource(shader, 2, source, NULL);
 	glCompileShader(shader);
 	glGetShaderiv(shader, GL_COMPILE_STATUS, &shader_compiled);
 	if (!shader_compiled)
 		ERROR("Failed to compile shader: %s", path);
-	free((char*)source);
+	free((char*)source[1]);
 	return shader;
 }
 
@@ -164,9 +178,15 @@ int gfx_init(void)
 	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
 		ERROR("SDL_Init failed: %s", SDL_GetError());
 
+#ifdef USE_GLES
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
+#else
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1);
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+#endif
 
 	sdl.format = SDL_AllocFormat(SDL_PIXELFORMAT_RGBA32);
 	sdl.window =  SDL_CreateWindow("XSystem4",
@@ -455,7 +475,7 @@ void gfx_init_texture_blank(struct texture *t, int w, int h)
 void gfx_copy_main_surface(struct texture *dst)
 {
 	init_texture(dst, main_surface.w, main_surface.h);
-	glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, 0, main_surface.w, main_surface.h, 0);
+	glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 0, 0, main_surface.w, main_surface.h, 0);
 }
 
 void gfx_delete_texture(struct texture *t)