diff --git a/libweston/renderer-gl/fragment.glsl b/libweston/renderer-gl/fragment.glsl
index d431096b9..1ea95b2c1 100644
--- a/libweston/renderer-gl/fragment.glsl
+++ b/libweston/renderer-gl/fragment.glsl
@@ -119,7 +119,7 @@ uniform samplerExternalOES tex;
 uniform sampler2D tex;
 #endif
 
-varying vec2 v_texcoord;
+varying HIGHPRECISION vec2 v_texcoord;
 uniform sampler2D tex1;
 uniform sampler2D tex2;
 uniform float view_alpha;
diff --git a/libweston/renderer-gl/vertex.glsl b/libweston/renderer-gl/vertex.glsl
index 03282e331..8b8019c3c 100644
--- a/libweston/renderer-gl/vertex.glsl
+++ b/libweston/renderer-gl/vertex.glsl
@@ -25,10 +25,21 @@
  * SOFTWARE.
  */
 
+/* Always use high-precision for vertex calculations */
+precision highp float;
+
+#ifdef GL_FRAGMENT_PRECISION_HIGH
+#define FRAG_PRECISION highp
+#else
+#define FRAG_PRECISION mediump
+#endif
+
 uniform mat4 proj;
 attribute vec2 position;
 attribute vec2 texcoord;
-varying vec2 v_texcoord;
+
+/* Match the varying precision to the fragment shader */
+varying FRAG_PRECISION vec2 v_texcoord;
 
 void main()
 {