diff --git a/tests/unit/type/string.tcl b/tests/unit/type/string.tcl
index 7122fd98..131a80ad 100644
--- a/tests/unit/type/string.tcl
+++ b/tests/unit/type/string.tcl
@@ -419,4 +419,26 @@ start_server {tags {"string"}} {
         r set foo bar
         r getrange foo 0 4294967297
     } {bar}
+
+    set rna1 {CACCTTCCCAGGTAACAAACCAACCAACTTTCGATCTCTTGTAGATCTGTTCTCTAAACGAACTTTAAAATCTGTGTGGCTGTCACTCGGCTGCATGCTTAGTGCACTCACGCAGTATAATTAATAACTAATTACTGTCGTTGACAGGACACGAGTAACTCGTCTATCTTCTGCAGGCTGCTTACGGTTTCGTCCGTGTTGCAGCCGATCATCAGCACATCTAGGTTTCGTCCGGGTGTG}
+    set rna2 {ATTAAAGGTTTATACCTTCCCAGGTAACAAACCAACCAACTTTCGATCTCTTGTAGATCTGTTCTCTAAACGAACTTTAAAATCTGTGTGGCTGTCACTCGGCTGCATGCTTAGTGCACTCACGCAGTATAATTAATAACTAATTACTGTCGTTGACAGGACACGAGTAACTCGTCTATCTTCTGCAGGCTGCTTACGGTTTCGTCCGTGTTGCAGCCGATCATCAGCACATCTAGGTTT}
+    set rnalcs {ACCTTCCCAGGTAACAAACCAACCAACTTTCGATCTCTTGTAGATCTGTTCTCTAAACGAACTTTAAAATCTGTGTGGCTGTCACTCGGCTGCATGCTTAGTGCACTCACGCAGTATAATTAATAACTAATTACTGTCGTTGACAGGACACGAGTAACTCGTCTATCTTCTGCAGGCTGCTTACGGTTTCGTCCGTGTTGCAGCCGATCATCAGCACATCTAGGTTT}
+
+    test {LCS string output with STRINGS option} {
+        r LCS STRINGS $rna1 $rna2
+    } $rnalcs
+
+    test {LCS len} {
+        r LCS LEN STRINGS $rna1 $rna2
+    } [string length $rnalcs]
+
+    test {LCS with KEYS option} {
+        r set virus1 $rna1
+        r set virus2 $rna2
+        r LCS KEYS virus1 virus2
+    } $rnalcs
+
+    test {LCS indexes} {
+        dict get [r LCS IDX KEYS virus1 virus2] matches
+    } {{{238 238} {239 239}} {{236 236} {238 238}} {{229 230} {236 237}} {{224 224} {235 235}} {{1 222} {13 234}}}
 }