diff --git a/gnucash/price-quotes.scm b/gnucash/price-quotes.scm
index c562987e9f..c73df2d02f 100644
--- a/gnucash/price-quotes.scm
+++ b/gnucash/price-quotes.scm
@@ -128,6 +128,9 @@
            (catch #t
              (lambda ()
                (gnc:debug "handling-request: " request)
+               (and (member (car request) '("currency" "alphavantage" "vanguard"))
+                    (not (getenv "ALPHAVANTAGE_API_KEY"))
+                    (throw 'need-alphavantage-key))
                ;; we need to display the first element (the method,
                ;; so it won't be quoted) and then write the rest
                (with-output-to-port (fdes->outport (gnc-process-get-fd quoter 0))
@@ -447,6 +450,11 @@
       (show-error (N_ "You are missing some needed Perl libraries.
 Run 'gnc-fq-update' as root to install them.")))
 
+     ((memq 'need-alphavantage-key fq-results)
+      (set! keep-going? #f)
+      (show-error (N_ "ERROR: ALPHAVANTAGE_API_KEY must be set for currency \
++ quotes; see https://wiki.gnucash.org/wiki/Online_Quotes#Source_Alphavantage.2C_US")))
+
      ((memq 'system-error fq-results)
       (set! keep-going? #f)
       (show-error (N_ "There was a system error while retrieving the price quotes.")))