diff --git a/11ty/biblio.ts b/11ty/biblio.ts
index 24a809fdb8..fcf5faca80 100644
--- a/11ty/biblio.ts
+++ b/11ty/biblio.ts
@@ -3,6 +3,8 @@ import { readFile } from "fs/promises";
 import { glob } from "glob";
 import uniq from "lodash-es/uniq";
 
+import { wrapAxiosRequest } from "./common";
+
 export const biblioPattern = /\[\[\??([\w-]+)\]\]/g;
 
 /** Compiles URLs from local biblio + specref for linking in Understanding documents. */
@@ -12,7 +14,7 @@ export async function getBiblio() {
       .replace(/^respecConfig\.localBiblio\s*=\s*/, "(")
       .replace("};", "})")
   );
-  
+
   const refs: string[] = [];
   for (const path of await glob(["guidelines/**/*.html", "understanding/*/*.html"])) {
     const content = await readFile(path, "utf8");
@@ -20,16 +22,18 @@ export async function getBiblio() {
     while ((match = biblioPattern.exec(content))) if (!localBiblio[match[1]]) refs.push(match[1]);
   }
   const uniqueRefs = uniq(refs);
-  
-  const response = await axios.get(`https://api.specref.org/bibrefs?refs=${uniqueRefs.join(",")}`);
+
+  const response = await wrapAxiosRequest(
+    axios.get(`https://api.specref.org/bibrefs?refs=${uniqueRefs.join(",")}`)
+  );
   const fullBiblio = {
     ...response.data,
     ...localBiblio,
   };
-  
+
   const resolvedRefs = Object.keys(fullBiblio);
   const unresolvedRefs = uniqueRefs.filter((ref) => !resolvedRefs.includes(ref));
   if (unresolvedRefs.length) console.warn(`Unresolved biblio refs: ${unresolvedRefs.join(", ")}`);
-  
+
   return fullBiblio;
 }
diff --git a/11ty/common.ts b/11ty/common.ts
index ade5d87f14..bda9ec4618 100644
--- a/11ty/common.ts
+++ b/11ty/common.ts
@@ -1,5 +1,7 @@
 /** @fileoverview Common functions used by multiple parts of the build process */
 
+import { AxiosError, type AxiosResponse } from "axios";
+
 import type { Guideline, Principle, SuccessCriterion } from "./guidelines";
 
 /** Generates an ID for heading permalinks. Equivalent to wcag:generate-id in base.xslt. */
@@ -28,3 +30,23 @@ export function wcagSort(
   }
   return 0;
 }
+
+/**
+ * Handles HTTP error responses from Axios requests in local dev;
+ * re-throws error during builds to fail loudly.
+ * This should only be used for non-critical requests that can tolerate null data
+ * without major side effects.
+ */
+export const wrapAxiosRequest = <T, D>(promise: Promise<AxiosResponse<T, D>>) =>
+  promise.catch((error) => {
+    if (!(error instanceof AxiosError) || !error.response || !error.request) throw error;
+    const { response, request } = error;
+    console.warn(
+      `AxiosError: status ${response.status} received from ${
+        request.protocol + "//" + request.host
+      }${request.path || ""}`
+    );
+
+    if (process.env.ELEVENTY_RUN_MODE === "build") throw error;
+    else return { data: null };
+  });