diff --git a/DESCRIPTION b/DESCRIPTION
index 227af42..efbae8e 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: NRWgauges
 Title: Web-scraping gauge (meta-)data from various providers in NRW, Germany
-Version: 0.3.0
+Version: 0.3.1
 Date: 2024-12-27
 Authors@R: 
     person("Dimitri", "Falk", , "falk.dimitri@eglv.de", role = c("aut", "cre"))
diff --git a/R/get_eglv_measurements.R b/R/get_eglv_measurements.R
index 83232bf..9f10103 100644
--- a/R/get_eglv_measurements.R
+++ b/R/get_eglv_measurements.R
@@ -58,8 +58,8 @@ get_eglv_measurements <- function(x = NULL,
   for (i in 1:n) {
 
     # query definition
-    query <- list(serial = ids[i],
-                  unit_name = par)
+    query <- list("serial" = ids[i],
+                  "unit_name" = par)
 
     # send request
     r_raw <- httr::GET(base_url, query = query)