diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 16fa57639..594757046 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2841,7 +2841,7 @@ ZSTD_compressBlock_splitBlock_internal(ZSTD_CCtx* zc,
     BYTE* op = (BYTE*)dst;
     size_t i = 0;
     size_t srcBytesTotal = 0;
-    U32* const partitions = zc->blockSplitCtx.partitions; /* size == ZSTD_MAX_NB_BLOCK_SPLITS */
+    U32* const partitions = zc->blockSplitCtx.partitions; /* splits plus the terminal boundary */
     SeqStore_t* const nextSeqStore = &zc->blockSplitCtx.nextSeqStore;
     SeqStore_t* const currSeqStore = &zc->blockSplitCtx.currSeqStore;
     size_t const numSplits = ZSTD_deriveBlockSplits(zc, partitions, nbSeq);
diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h
index 93b6d4525..5ed9b02bd 100644
--- a/lib/compress/zstd_compress_internal.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -465,7 +465,8 @@ typedef struct {
     SeqStore_t currSeqStore;
     SeqStore_t nextSeqStore;
 
-    U32 partitions[ZSTD_MAX_NB_BLOCK_SPLITS];
+    /* One terminal boundary follows the at most ZSTD_MAX_NB_BLOCK_SPLITS splits. */
+    U32 partitions[ZSTD_MAX_NB_BLOCK_SPLITS + 1];
     ZSTD_entropyCTablesMetadata_t entropyMetadata;
 } ZSTD_blockSplitCtx;
 
diff --git a/rust/src/zstd_compress_block_split.rs b/rust/src/zstd_compress_block_split.rs
index 0a7ed73ee..e360c7a80 100644
--- a/rust/src/zstd_compress_block_split.rs
+++ b/rust/src/zstd_compress_block_split.rs
@@ -421,6 +421,47 @@ mod tests {
         assert_eq!(partitions[0], 600);
     }
 
+    #[test]
+    fn an_estimation_error_in_any_candidate_prevents_the_split() {
+        for error_index in 0..3 {
+            let mut sequences = vec![SeqDef::default(); 600];
+            let mut partitions = [u32::MAX; 2];
+            let mut calls = 0;
+            let splits = unsafe {
+                run_search(&mut sequences, 0, 0, &mut partitions, |_| {
+                    let current_call = calls;
+                    calls += 1;
+                    if current_call == error_index {
+                        ERROR(ZstdErrorCode::Generic)
+                    } else {
+                        0
+                    }
+                })
+            };
+
+            assert_eq!(splits, 0, "error in candidate {error_index}");
+            assert_eq!(calls, 3, "error in candidate {error_index}");
+            assert_eq!(partitions[0], 600, "error in candidate {error_index}");
+        }
+    }
+
+    #[test]
+    fn equal_estimated_cost_does_not_split() {
+        let mut sequences = vec![SeqDef::default(); 600];
+        let mut partitions = [u32::MAX; 2];
+        let mut calls = 0;
+        let splits = unsafe {
+            run_search(&mut sequences, 0, 0, &mut partitions, |_| {
+                calls += 1;
+                0
+            })
+        };
+
+        assert_eq!(splits, 0);
+        assert_eq!(calls, 3);
+        assert_eq!(partitions[0], 600);
+    }
+
     #[test]
     fn derived_views_keep_long_length_metadata_in_their_ranges() {
         let mut sequences = vec![SeqDef::default(); 600];