diff --git a/modules/core/src/main/java/org/locationtech/jts/geom/MultiPoint.java b/modules/core/src/main/java/org/locationtech/jts/geom/MultiPoint.java
index 7fb61c1e8e..0080a44761 100644
--- a/modules/core/src/main/java/org/locationtech/jts/geom/MultiPoint.java
+++ b/modules/core/src/main/java/org/locationtech/jts/geom/MultiPoint.java
@@ -87,10 +87,6 @@ protected MultiPoint reverseInternal() {
     }
     return new MultiPoint(points, factory);
   }
-  
-  public boolean isValid() {
-    return true;
-  }
 
   public boolean equalsExact(Geometry other, double tolerance) {
     if (!isEquivalentClass(other)) {
diff --git a/modules/tests/src/test/resources/testxml/general/TestValid.xml b/modules/tests/src/test/resources/testxml/general/TestValid.xml
index cd201977d5..4ef18654aa 100644
--- a/modules/tests/src/test/resources/testxml/general/TestValid.xml
+++ b/modules/tests/src/test/resources/testxml/general/TestValid.xml
@@ -60,7 +60,7 @@
    </case>
 
    <case>
-      <desc>P - repeated points</desc>
+      <desc>mP - repeated points</desc>
       <a>
     MULTIPOINT((10 10), (20 20), (30 30), (10 10))
   </a>
@@ -69,6 +69,16 @@
       </test>
    </case>
 
+   <case>
+      <desc>mP - invalid point</desc>
+      <a>
+    MULTIPOINT((10 10), (20 20), (30 30), (10 NaN))
+  </a>
+      <test>
+         <op name="isValid" arg1="A">    false  </op>
+      </test>
+   </case>
+
    <case>
       <desc>L - empty</desc>
       <a>
@@ -141,6 +151,14 @@ LINESTRING (40 180, 120 120, 140 200, 140 200, 200 140, 240 200)
       </test>
    </case>
 
+   <case>
+      <desc>mL - MultiLinestring with invalid point</desc>
+      <a>MULTILINESTRING((1 1, 2 NaN, 0 0))</a>
+      <test>
+         <op name="isValid" arg1="A">      false      </op>
+      </test>
+   </case>
+
    <case>
       <desc>A - zero-area polygon </desc>
       <a>POLYGON ((0 0, 0 0, 0 0, 0 0, 0 0))</a>