diff --git a/scripts/01-convert-pdfs.sh b/scripts/01-convert-pdfs.sh
index 05679fd..74e6408 100755
--- a/scripts/01-convert-pdfs.sh
+++ b/scripts/01-convert-pdfs.sh
@@ -115,7 +115,9 @@ convert_one_pdf() {
             num=$(printf '%s' "$bn" | sed -E 's/^p-([0-9]+)\.png$/\1/')
             if [[ "$num" =~ ^[0-9]+$ ]]; then
                 local padded
-                padded=$(printf '%03d' "$num")
+                # Force decimal interpretation: leading zeros would make bash
+                # treat "008" as invalid octal under printf '%03d'.
+                padded=$(printf '%03d' "$((10#$num))")
                 local new_name="p-$padded.png"
                 if [[ "$bn" != "$new_name" ]]; then
                     mv "$f" "$png_dir/$new_name"
diff --git a/web/app/api/crop/route.ts b/web/app/api/crop/route.ts
index 23d43d9..098d088 100644
--- a/web/app/api/crop/route.ts
+++ b/web/app/api/crop/route.ts
@@ -57,7 +57,12 @@ export async function GET(req: NextRequest) {
   const format = (u.searchParams.get("format") ?? "webp").toLowerCase();
   const tight = u.searchParams.get("tight") !== "0";
 
-  // Resolve source PNG
+  // Resolve source PNG.
+  // Two conventions exist in the corpus:
+  //   1-based:  page=1 → p-001.png  (most docs)
+  //   0-based:  page=1 → p-000.png  (~34 docs converted with pdftoppm -f 0)
+  // Try the 1-based path first; if the file doesn't exist, fall back to
+  // 0-based (page - 1). Idempotent — if both exist, 1-based wins.
   let pngPath: string;
   if (pngParam) {
     if (pngParam.includes("..")) return badRequest("png param: invalid path");
@@ -71,8 +76,12 @@ export async function GET(req: NextRequest) {
       pageNum = parseInt(pageStr, 10);
     }
     if (!Number.isFinite(pageNum) || pageNum < 1) return badRequest("bad page");
+    const docDir = path.join(PROCESSING, "png", doc);
+    const oneBased = path.join(docDir, `p-${String(pageNum).padStart(3, "0")}.png`);
+    const zeroBased = path.join(docDir, `p-${String(pageNum - 1).padStart(3, "0")}.png`);
+    const { existsSync } = await import("node:fs");
+    pngPath = existsSync(oneBased) ? oneBased : (existsSync(zeroBased) ? zeroBased : oneBased);
     pageStr = `p-${String(pageNum).padStart(3, "0")}`;
-    pngPath = path.join(PROCESSING, "png", doc, `${pageStr}.png`);
   }
 
   let buf: Buffer;