diff --git a/kmod/src/srch.c b/kmod/src/srch.c
index b113614c..54b0711d 100644
--- a/kmod/src/srch.c
+++ b/kmod/src/srch.c
@@ -1481,10 +1481,11 @@ static int kway_merge(struct super_block *sb,
 	int ind;
 	int i;
 
-	if (WARN_ON_ONCE(nr <= 1))
+	if (WARN_ON_ONCE(nr <= 0))
 		return -EINVAL;
 
-	nr_parents = roundup_pow_of_two(nr) - 1;
+	/* always at least one parent for single leaf */
+	nr_parents = max_t(unsigned long, 1, roundup_pow_of_two(nr) - 1);
 	/* root at [1] for easy sib/parent index calc, final pad for odd sib */
 	nr_nodes = 1 + nr_parents + nr + 1;
 	tnodes = __vmalloc(nr_nodes * sizeof(struct tourn_node),
diff --git a/tests/golden/srch-basic-functionality b/tests/golden/srch-basic-functionality
index c46d1701..e135bb58 100644
--- a/tests/golden/srch-basic-functionality
+++ b/tests/golden/srch-basic-functionality
@@ -2,6 +2,7 @@
 == update existing xattr
 == remove an xattr
 == remove xattr with files
+== trigger small log merges by rotating single block with unmount
 == create entries in current log
 == delete small fraction
 == remove files
diff --git a/tests/tests/srch-basic-functionality.sh b/tests/tests/srch-basic-functionality.sh
index 55c709f5..1b982489 100644
--- a/tests/tests/srch-basic-functionality.sh
+++ b/tests/tests/srch-basic-functionality.sh
@@ -42,6 +42,31 @@ echo "== remove xattr with files"
 rm -f "$T_D0/"{create,update}
 diff_srch_find scoutfs.srch.test
 
+echo "== trigger small log merges by rotating single block with unmount"
+sv=$(t_server_nr)
+i=1
+while [ "$i" -lt "8" ]; do
+	for nr in $(t_fs_nrs); do
+		# not checking, can go over limit by fs_nrs
+		((i++))
+
+		if [ $nr == $sv ]; then
+			continue;
+		fi
+
+		eval path="\$T_D${nr}/single-block-$i"
+		touch "$path"
+		setfattr -n scoutfs.srch.single-block-logs -v $i "$path"
+		t_umount $nr
+		t_mount $nr
+
+		((i++))
+	done
+done
+# wait for srch compaction worker delay
+sleep 10
+rm -rf "$T_D0/single-block-*"
+
 echo "== create entries in current log"
 DIR="$T_D0/dir"
 NR=$((LOG / 4))