diff --git a/src/cairo-gl-composite.c b/src/cairo-gl-composite.c
index 382b13b5e..5bce04d58 100644
--- a/src/cairo-gl-composite.c
+++ b/src/cairo-gl-composite.c
@@ -656,8 +656,8 @@ _cairo_gl_composite_emit_vertex (cairo_gl_context_t *ctx,
     *vb++ = x;
     *vb++ = y;
 
-    _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y, alpha);
-    _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_MASK  ], &vb, x, y, alpha);
+    _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y);
+    _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_MASK  ], &vb, x, y);
 
     if (ctx->spans) {
 	union fi {
@@ -706,7 +706,7 @@ _cairo_gl_composite_emit_glyph_vertex (cairo_gl_context_t *ctx,
     *vb++ = x;
     *vb++ = y;
 
-    _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y, 0);
+    _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y);
 
     *vb++ = glyph_x;
     *vb++ = glyph_y;
diff --git a/src/cairo-gl-operand.c b/src/cairo-gl-operand.c
index f0f765636..a7e187ea4 100644
--- a/src/cairo-gl-operand.c
+++ b/src/cairo-gl-operand.c
@@ -600,8 +600,7 @@ void
 _cairo_gl_operand_emit (cairo_gl_operand_t *operand,
                         GLfloat ** vb,
                         GLfloat x,
-                        GLfloat y,
-                        uint8_t alpha)
+                        GLfloat y)
 {
     switch (operand->type) {
     default:
diff --git a/src/cairo-gl-private.h b/src/cairo-gl-private.h
index 6d8aab86c..902717860 100644
--- a/src/cairo-gl-private.h
+++ b/src/cairo-gl-private.h
@@ -636,8 +636,7 @@ cairo_private void
 _cairo_gl_operand_emit (cairo_gl_operand_t *operand,
                         GLfloat ** vb,
                         GLfloat x,
-                        GLfloat y,
-                        uint8_t alpha);
+                        GLfloat y);
 
 cairo_private void
 _cairo_gl_operand_copy (cairo_gl_operand_t *dst,