diff --git a/src/main/java/org/apache/commons/text/similarity/CosineSimilarity.java b/src/main/java/org/apache/commons/text/similarity/CosineSimilarity.java
index 2c5a123b72..73fff3077b 100644
--- a/src/main/java/org/apache/commons/text/similarity/CosineSimilarity.java
+++ b/src/main/java/org/apache/commons/text/similarity/CosineSimilarity.java
@@ -86,7 +86,7 @@ public Double cosineSimilarity(final Map<CharSequence, Integer> leftVector, fina
      * @return The dot product.
      */
     private double dot(final Map<CharSequence, Integer> leftVector, final Map<CharSequence, Integer> rightVector, final Set<CharSequence> intersection) {
-        long dotProduct = 0;
+        double dotProduct = 0;
         for (final CharSequence key : intersection) {
             dotProduct += leftVector.get(key) * (long) rightVector.get(key);
         }
diff --git a/src/test/java/org/apache/commons/text/similarity/CosineSimilarityTest.java b/src/test/java/org/apache/commons/text/similarity/CosineSimilarityTest.java
index 0f95908748..87769405de 100644
--- a/src/test/java/org/apache/commons/text/similarity/CosineSimilarityTest.java
+++ b/src/test/java/org/apache/commons/text/similarity/CosineSimilarityTest.java
@@ -24,9 +24,21 @@
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 class CosineSimilarityTest {
 
+    @ParameterizedTest
+    @ValueSource(ints = {1, Integer.MAX_VALUE, Integer.MIN_VALUE})
+    void testCosineSimilarityOfIdenticalVectors(final int value) {
+        final Map<CharSequence, Integer> vector = new HashMap<>();
+        vector.put("a", value);
+        vector.put("b", value);
+        vector.put("c", value);
+        assertEquals(1.0, CosineSimilarity.INSTANCE.cosineSimilarity(vector, vector), 1e-12);
+    }
+
     @Test
     void testCosineSimilarityReturningDoubleWhereByteValueIsZero() {
         final Map<CharSequence, Integer> hashMap = new HashMap<>();