diff --git a/include/sway/desktop/fx_renderer.h b/include/sway/desktop/fx_renderer.h
index 39c1a25b..889d8a82 100644
--- a/include/sway/desktop/fx_renderer.h
+++ b/include/sway/desktop/fx_renderer.h
@@ -13,8 +13,7 @@ struct gles2_tex_shader {
 	GLint alpha;
 	GLint pos_attrib;
 	GLint tex_attrib;
-	GLint width;
-	GLint height;
+	GLint size;
 	GLint position;
 	GLint radius;
 };
diff --git a/include/sway/desktop/shaders.h b/include/sway/desktop/shaders.h
index 4ff9ca42..6a9f8863 100644
--- a/include/sway/desktop/shaders.h
+++ b/include/sway/desktop/shaders.h
@@ -45,16 +45,15 @@ const GLchar tex_fragment_src_rgba[] =
 "uniform sampler2D tex;\n"
 "uniform float alpha;\n"
 "\n"
-"uniform float width;\n"
-"uniform float height;\n"
+"uniform vec2 size;\n"
 "uniform vec2 position;\n"
 "uniform float radius;\n"
 "\n"
 "void main() {\n"
 "   gl_FragColor = texture2D(tex, v_texcoord) * alpha;\n"
-"   vec2 corner_distance = min(gl_FragCoord.xy - position, position + vec2(width, height) - gl_FragCoord.xy);\n"
+"   vec2 corner_distance = min(gl_FragCoord.xy - position, size + position - gl_FragCoord.xy);\n"
 "   if (max(corner_distance.x, corner_distance.y) < radius) {\n"
-"		float d = radius - distance(corner_distance, vec2(radius, radius));\n"
+"		float d = radius - distance(corner_distance, vec2(radius));\n"
 "		float smooth = smoothstep(-1.0f, 0.5f, d);\n"
 "		gl_FragColor = mix(vec4(0), gl_FragColor, smooth);\n"
 "   }\n"
@@ -66,38 +65,37 @@ const GLchar tex_fragment_src_rgbx[] =
 "uniform sampler2D tex;\n"
 "uniform float alpha;\n"
 "\n"
-"uniform float width;\n"
-"uniform float height;\n"
+"uniform vec2 size;\n"
 "uniform vec2 position;\n"
 "uniform float radius;\n"
 "\n"
 "void main() {\n"
 "	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0) * alpha;\n"
-"   vec2 corner_distance = min(gl_FragCoord.xy - position, position + vec2(width, height) - gl_FragCoord.xy);\n"
+"   vec2 corner_distance = min(gl_FragCoord.xy - position, position + size - gl_FragCoord.xy);\n"
 "   if (max(corner_distance.x, corner_distance.y) < radius) {\n"
-"		float d = radius - distance(corner_distance, vec2(radius, radius));\n"
+"		float d = radius - distance(corner_distance, vec2(radius));\n"
 "		float smooth = smoothstep(-1.0f, 0.5f, d);\n"
 "		gl_FragColor = mix(vec4(0), gl_FragColor, smooth);\n"
 "   }\n"
 "}\n";
 
 const GLchar tex_fragment_src_external[] =
-"#extension GL_OES_EGL_image_external : require\n\n"
+"#extension GL_OES_EGL_image_external : require\n"
+"\n"
 "precision mediump float;\n"
 "varying vec2 v_texcoord;\n"
 "uniform samplerExternalOES texture0;\n"
 "uniform float alpha;\n"
 "\n"
-"uniform float width;\n"
-"uniform float height;\n"
+"uniform vec2 size;\n"
 "uniform vec2 position;\n"
 "uniform float radius;\n"
 "\n"
 "void main() {\n"
 "	gl_FragColor = texture2D(texture0, v_texcoord) * alpha;\n"
-"   vec2 corner_distance = min(gl_FragCoord.xy - position, position + vec2(width, height) - gl_FragCoord.xy);\n"
+"   vec2 corner_distance = min(gl_FragCoord.xy - position, position + size - gl_FragCoord.xy);\n"
 "   if (max(corner_distance.x, corner_distance.y) < radius) {\n"
-"		float d = radius - distance(corner_distance, vec2(radius, radius));\n"
+"		float d = radius - distance(corner_distance, vec2(radius));\n"
 "		float smooth = smoothstep(-1.0f, 0.5f, d);\n"
 "		gl_FragColor = mix(vec4(0), gl_FragColor, smooth);\n"
 "   }\n"
diff --git a/sway/desktop/fx_renderer.c b/sway/desktop/fx_renderer.c
index 6810fa26..90ed8957 100644
--- a/sway/desktop/fx_renderer.c
+++ b/sway/desktop/fx_renderer.c
@@ -86,8 +86,7 @@ bool init_frag_shader(struct gles2_tex_shader *shader, GLuint prog) {
 	shader->alpha = glGetUniformLocation(prog, "alpha");
 	shader->pos_attrib = glGetAttribLocation(prog, "pos");
 	shader->tex_attrib = glGetAttribLocation(prog, "texcoord");
-	shader->width = glGetUniformLocation(prog, "width");
-	shader->height = glGetUniformLocation(prog, "height");
+	shader->size = glGetUniformLocation(prog, "size");
 	shader->position = glGetUniformLocation(prog, "position");
 	shader->radius = glGetUniformLocation(prog, "radius");
 	return true;
@@ -277,8 +276,7 @@ bool fx_render_subtexture_with_matrix(struct fx_renderer *renderer, struct wlr_t
 	glUniform1f(shader->alpha, alpha);
 
 	// rounded corners
-	glUniform1f(shader->width, dst_box->width);
-	glUniform1f(shader->height, dst_box->height);
+	glUniform2f(shader->size, dst_box->width, dst_box->height);
 	glUniform2f(shader->position, dst_box->x, dst_box->y);
 	glUniform1f(shader->radius, radius);