diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp
index b49fd38d64d..a85e4c42ae3 100644
--- a/src/mesa/main/shader_query.cpp
+++ b/src/mesa/main/shader_query.cpp
@@ -506,7 +506,7 @@ _mesa_program_resource_array_size(struct gl_program_resource *res)
 static bool
 valid_array_index(const GLchar *name, unsigned *array_index)
 {
-   unsigned idx = 0;
+   long idx = 0;
    const GLchar *out_base_name_end;
 
    idx = parse_program_resource_name(name, &out_base_name_end);