diff --git a/crates/sc-consensus-subspace/src/lib.rs b/crates/sc-consensus-subspace/src/lib.rs
index 0cf2bca32b..bc2c1d7738 100644
--- a/crates/sc-consensus-subspace/src/lib.rs
+++ b/crates/sc-consensus-subspace/src/lib.rs
@@ -802,6 +802,21 @@ where
                 .ok_or(Error::<Block::Header>::MissingSalt(hash))?
                 .salt;
 
+            // TODO: Hack for Gemini 1b launch. Solution range should have been updated already.
+            if *block.header.number() >= 33_671_u32.into()
+                && self.client.info().genesis_hash.as_ref() == GEMINI_1B_GENESIS_HASH
+                && solution_range == 12_009_599_006_321_322_u64
+            {
+                debug!(
+                    target: "subspace",
+                    "Ignoring block from non-canonical fork"
+                );
+                return Err(Error::<Block::Header>::InvalidSolutionRange(
+                    block.post_hash.unwrap_or_default(),
+                )
+                .into());
+            }
+
             // We add one to the current slot to allow for some small drift.
             // FIXME https://github.com/paritytech/substrate/issues/1019 in the future, alter this
             //  queue to allow deferring of headers