diff --git a/src/compiler/glsl/glsl_to_nir.cpp b/src/compiler/glsl/glsl_to_nir.cpp
index a51d39c4753..d21ad90505e 100644
--- a/src/compiler/glsl/glsl_to_nir.cpp
+++ b/src/compiler/glsl/glsl_to_nir.cpp
@@ -270,6 +270,7 @@ nir_visitor::nir_visitor(gl_context *ctx, nir_shader *shader)
    this->result = NULL;
    this->impl = NULL;
    this->deref = NULL;
+   this->sig = NULL;
    memset(&this->b, 0, sizeof(this->b));
 }