diff --git a/src/Graphics/OpenGLContext/GLSL/glsl_SpecialShadersFactory.cpp b/src/Graphics/OpenGLContext/GLSL/glsl_SpecialShadersFactory.cpp
index 0a599c76..df906d55 100644
--- a/src/Graphics/OpenGLContext/GLSL/glsl_SpecialShadersFactory.cpp
+++ b/src/Graphics/OpenGLContext/GLSL/glsl_SpecialShadersFactory.cpp
@@ -370,47 +370,47 @@ namespace glsl {
 			"    return textureSize(tex, 0);                                                    \n"
 			"#endif                                                                             \n"
 			"}                                                                                  \n"
-			"vec2 norm2denorm(in vec2 uv, in ivec2 texture_size)                                \n"
+			"mediump vec2 norm2denorm(in mediump vec2 uv, in ivec2 texture_size)                \n"
 			"{                                                                                  \n"
-			"       return uv * texture_size - 0.5f;                                            \n"
+			"       return uv * vec2(texture_size) - 0.5f;                                      \n"
 			"}                                                                                  \n"
-			"ivec2 denorm2idx(in vec2 d_uv)                                                     \n"
+			"ivec2 denorm2idx(in mediump vec2 d_uv)                                             \n"
 			"{                                                                                  \n"
 			"       return ivec2(floor(d_uv));                                                  \n"
 			"}                                                                                  \n"
-			"ivec2 norm2idx(in vec2 uv, in ivec2 texture_size)                                  \n"
+			"ivec2 norm2idx(in mediump vec2 uv, in ivec2 texture_size)                          \n"
 			"{                                                                                  \n"
 			"       return denorm2idx(norm2denorm(uv, texture_size));                           \n"
 			"}                                                                                  \n"
-			"vec2 idx2norm(in ivec2 idx, in ivec2 texture_size)                                 \n"
+			"mediump vec2 idx2norm(in ivec2 idx, in ivec2 texture_size)                         \n"
 			"{                                                                                  \n"
-			"       vec2 denorm_uv = vec2(idx) + 0.5f;                                          \n"
-			"       return denorm_uv / texture_size;                                            \n"
+			"       mediump vec2 denorm_uv = vec2(idx) + 0.5f;                                  \n"
+			"       return denorm_uv / vec2(texture_size);                                      \n"
 			"}                                                                                  \n"
-			"vec4 texel_fetch(in sampler2D tex, in ivec2 idx, in ivec2 texture_size)            \n"
+			"mediump vec4 texel_fetch(in sampler2D tex, in ivec2 idx, in ivec2 texture_size)    \n"
 			"{                                                                                  \n"
-			"       vec2 uv = idx2norm(idx, texture_size);                                      \n"
+			"       mediump vec2 uv = idx2norm(idx, texture_size);                              \n"
 			"       return texture2D(tex, uv);                                                  \n"
 			"}                                                                                  \n"
-			"vec4 hybridFilter(in sampler2D tex, in vec2 uv)                                    \n"
+			"mediump vec4 hybridFilter(in sampler2D tex, in mediump vec2 uv)                    \n"
 			"{                                                                                  \n"
 			"       ivec2 texSize = getTextureSize(tex);                                        \n"
-			"       vec2 denorm_uv = norm2denorm(uv,texSize);                                   \n"
+			"       mediump vec2 denorm_uv = norm2denorm(uv,texSize);                           \n"
 			"       ivec2 idx_low = denorm2idx(denorm_uv);                                      \n"
-			"       vec2 ratio = denorm_uv - idx_low;                                           \n"
+			"       mediump vec2 ratio = denorm_uv - vec2(idx_low);                             \n"
 			"       ivec2 rounded_idx = idx_low + ivec2(step(0.5f, ratio));                     \n"
 			"                                                                                   \n"
 			"       ivec2 idx00 = idx_low;                                                      \n"
-			"       vec4 t00 = texel_fetch(tex, idx00, texSize);                                \n"
+			"       mediump vec4 t00 = texel_fetch(tex, idx00, texSize);                        \n"
 			"                                                                                   \n"
 			"       ivec2 idx01 = idx00 + ivec2(0, 1);                                          \n"
-			"       vec4 t01 = texel_fetch(tex, idx01, texSize);                                \n"
+			"       mediump vec4 t01 = texel_fetch(tex, idx01, texSize);                        \n"
 			"                                                                                   \n"
 			"       ivec2 idx10 = idx00 + ivec2(1, 0);                                          \n"
-			"       vec4 t10 = texel_fetch(tex, idx10, texSize);                                \n"
+			"       mediump vec4 t10 = texel_fetch(tex, idx10, texSize);                        \n"
 			"                                                                                   \n"
 			"       ivec2 idx11 = idx00 + ivec2(1, 1);                                          \n"
-			"       vec4 t11 = texel_fetch(tex, idx11, texSize);                                \n"
+			"       mediump vec4 t11 = texel_fetch(tex, idx11, texSize);                        \n"
 			"                                                                                   \n"
 			"       /*                                                                          \n"
 			"       * radius is the distance from the edge where interpolation happens.         \n"
@@ -428,9 +428,9 @@ namespace glsl {
 			"                                                                                     \n"
 			"       // Here, fwidth() is used to estimte how much denorm_uv changes per fragment. \n"
 			"       // But we divide it by 2, since fwidth() is adding abs(dx) + abs(dy).         \n"
-			"       vec2 fragment_size = fwidth(denorm_uv) / 2.0f;                                \n"
+			"       mediump vec2 fragment_size = fwidth(denorm_uv) / 2.0f;                        \n"
 			"                                                                                     \n"
-			"       float is_frag_gt1, radius;                                                    \n"
+			"       mediump float is_frag_gt1, radius;                                            \n"
 			"       // Do nothing if fragment is greater than 1 texel                             \n"
 			"       // Don't make the transition more than one fragment (+/- 0.5 fragment)        \n"
 			"       is_frag_gt1 = step(1.0f, fragment_size.s);                                    \n"
@@ -443,8 +443,8 @@ namespace glsl {
 			"           0.5f + radius,	ratio.t) * (1.0 - is_frag_gt1);                           \n"
 			"                                                                                     \n"
 			"       // interpolate first on S direction then on T.                                \n"
-			"       vec4 top = mix(t00, t10, ratio.s);                                            \n"
-			"       vec4 bottom = mix(t01, t11, ratio.s);                                         \n"
+			"       mediump vec4 top = mix(t00, t10, ratio.s);                                    \n"
+			"       mediump vec4 bottom = mix(t01, t11, ratio.s);                                 \n"
 			"       return mix(top, bottom, ratio.t);                                             \n"
 			"}                                                                                    \n"
 			;