diff --git a/conda.recipe/meta.yaml b/conda.recipe/meta.yaml
index 3a0d3c1..27cc945 100644
--- a/conda.recipe/meta.yaml
+++ b/conda.recipe/meta.yaml
@@ -1,5 +1,5 @@
-{% set version = "1.8.0" %}
-{% set sha256 = "915a55840e1283fa61db9507d34af479d1f8a985ed7ab56aa7ccc86716a84780" %}
+{% set version = "1.8.1" %}
+{% set sha256 = "d36f700264e0636d722c783d15e5722792c460235fccb748fbe73c2910a949c8" %}
 
 package:
   name: syri
@@ -17,8 +17,8 @@ build:
 
 requirements:
   build:
-    - {{ compiler('c') }}
     - {{ compiler('cxx') }}
+    - {{ stdlib("cxx") }}
   host:
     - python >=3.9
     - setuptools
@@ -51,3 +51,5 @@ about:
 extra:
   maintainers:
     - mnshgl0110
+  skip-lints:
+    - compiler_needs_stdlib_c
diff --git a/pyproject.toml b/pyproject.toml
index 7674dfa..82f387b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,6 @@ dependencies = [
 	"igraph",
 	"longestrunsubsequence",
 	'pysam',
-	"pulp",
 ]
 dynamic = ["version"]
 
diff --git a/syri/__init__.py b/syri/__init__.py
index 29654ee..2d986fc 100644
--- a/syri/__init__.py
+++ b/syri/__init__.py
@@ -1 +1 @@
-__version__ = "1.8.0"
+__version__ = "1.8.1"
diff --git a/syri/pyxFiles/synsearchFunctions.pyx b/syri/pyxFiles/synsearchFunctions.pyx
index 892b50b..1058a79 100644
--- a/syri/pyxFiles/synsearchFunctions.pyx
+++ b/syri/pyxFiles/synsearchFunctions.pyx
@@ -865,20 +865,25 @@ def syri(chromo, threshold, coords, cwdPath, bRT, prefix, tUC, tUP, invgl, tdgl,
 ########################################################################################################################
 
 
-cpdef apply_TS(const long[:] astart, const long[:] aend, const long[:] bstart, const long[:] bend, int threshold, int mxgap = 100000000000):
+# builds a matrix indicating which alignments are consistent with one another
+cpdef apply_TS(const long[:] astart, const long[:] aend, const long[:] bstart, const long[:] bend, int threshold, int mxgap = 100_000_000_000):
     cdef:
-        Py_ssize_t                              i, j,  n = len(astart)
+        Py_ssize_t                              i, j # init loop vars
+        Py_ssize_t                              n = len(astart)
         cpp_map[long, cpp_deq[long]]            df
-        cpp_map[long, cpp_deq[long]].iterator   mapit # Leon: unused?
+        #cpp_map[long, cpp_deq[long]].iterator   mapit # Leon: unused?
+    # handle single aln case
+    if n == 1:
+        return {0:[0]}
+
     for i in range(<Py_ssize_t> n):
         for j in range(<Py_ssize_t> i+1, <Py_ssize_t> n):
-            if (astart[j] - aend[i]) < mxgap:        # Select only alignments with small gaps
-                if (astart[j] - astart[i]) > threshold:
+            if ((astart[j] - aend[i]) < mxgap) and ((bstart[j] - bend[i]) < mxgap):        # Select only alignments with small gaps
+                if (astart[j] - astart[i]) > threshold: # check compatibility on a
                     if (aend[j] - aend[i]) > threshold:
-                        if (bstart[j] - bend[i]) < mxgap:        # Select only alignments with small gaps
-                            if (bstart[j] - bstart[i]) > threshold:
-                                if (bend[j] - bend[i]) > threshold:
-                                    df[i].push_back(j)
+                        if (bstart[j] - bstart[i]) > threshold: # check compatibility on b
+                            if (bend[j] - bend[i]) > threshold:
+                                df[i].push_back(j) # add to list of compatible alns
     out = {}
     for i in range(n):
         if df.count(i)== 1: