diff --git a/program.h b/program.h
index 8d4088dddde..44cf3456355 100644
--- a/program.h
+++ b/program.h
@@ -33,7 +33,7 @@ struct glsl_shader {
    GLboolean DeletePending;
    GLboolean CompileStatus;
    const GLchar *Source;  /**< Source code string */
-   GLuint SourceLen;
+   size_t SourceLen;
    GLchar *InfoLog;
 
    struct exec_list ir;