diff --git a/crates/psd/src/filter_effects.rs b/crates/psd/src/filter_effects.rs
index e8b5efb698..cadb3ac8d0 100644
--- a/crates/psd/src/filter_effects.rs
+++ b/crates/psd/src/filter_effects.rs
@@ -170,7 +170,10 @@ impl FilterEffects {
             let pad = ((4 - len % 4) % 4).min(r.remaining() as u64);
             r.skip(pad as usize)?;
             let rest = r.peek_rest();
-            if rest.iter().all(|&b| b == 0) && rest.len() <= 3 {
+            // Padding is at most three bytes. Check the length before scanning the suffix for
+            // zeros: otherwise each iteration scans the whole remaining buffer, which is
+            // quadratic when a block contains many empty sections.
+            if rest.len() <= 3 && rest.iter().all(|&b| b == 0) {
                 break;
             }
             if rest.len() < 8 {