diff --git a/src/mesa/tnl/t_vb_program.c b/src/mesa/tnl/t_vb_program.c
index 76f8fde3f52..7e7c59ae07b 100644
--- a/src/mesa/tnl/t_vb_program.c
+++ b/src/mesa/tnl/t_vb_program.c
@@ -311,7 +311,7 @@ run_vp( struct gl_context *ctx, struct tnl_pipeline_stage *stage )
    struct vp_stage_data *store = VP_STAGE_DATA(stage);
    struct vertex_buffer *VB = &tnl->vb;
    struct gl_vertex_program *program = ctx->VertexProgram._Current;
-   struct gl_program_machine machine;
+   struct gl_program_machine machine = { 0 };
    GLuint outputs[VERT_RESULT_MAX], numOutputs;
    GLuint i, j;