diff --git a/modules/core/src/test/java/org/locationtech/jts/simplify/DouglasPeuckerSimplifierTest.java b/modules/core/src/test/java/org/locationtech/jts/simplify/DouglasPeuckerSimplifierTest.java
index df940a62df..bfd8f56b82 100644
--- a/modules/core/src/test/java/org/locationtech/jts/simplify/DouglasPeuckerSimplifierTest.java
+++ b/modules/core/src/test/java/org/locationtech/jts/simplify/DouglasPeuckerSimplifierTest.java
@@ -53,8 +53,8 @@ public void testPolygonReductionWithSplit() {
   
   public void testPolygonReduction() {
     checkDP("POLYGON ((120 120, 121 121, 122 122, 220 120, 180 199, 160 200, 140 199, 120 120))",
-        10.0, 
-        "POLYGON ((120 120, 220 120, 180 199, 160 200, 140 199, 120 120)))");
+        10, 
+        "POLYGON ((120 120, 220 120, 180 199, 160 200, 140 199, 120 120))");
   }
   
   public void testPolygonWithTouchingHole() {
diff --git a/modules/core/src/test/java/org/locationtech/jts/simplify/TopologyPreservingSimplifierTest.java b/modules/core/src/test/java/org/locationtech/jts/simplify/TopologyPreservingSimplifierTest.java
index 06cdceca71..4e36250216 100644
--- a/modules/core/src/test/java/org/locationtech/jts/simplify/TopologyPreservingSimplifierTest.java
+++ b/modules/core/src/test/java/org/locationtech/jts/simplify/TopologyPreservingSimplifierTest.java
@@ -158,6 +158,11 @@ public void testLinearRingRemoveEndpoint() throws Exception {
         );
   }
   
+  public void testPolygonKeepFlatEndpointWithTouch() throws Exception {
+    checkTPSNoChange("POLYGON ((0 0, 5 2.05, 10 0, 10 10, 0 10, 0 0),  (5 2.1, 6 2, 6 4, 4 4, 4 2, 5 2.1))",
+        0.1 );
+  }
+  
   public void testPolygonKeepEndpointWithCross() throws Exception {
     checkTPS(
       "POLYGON ((50 52, 60 50, 90 60, 90 10, 10 10, 10 90, 60 90, 50 55, 40 80, 20 60, 40 50, 50 52))",