diff --git a/build.gradle b/build.gradle
index 115e52351..cbb6e2ff4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,7 +7,7 @@ group 'com.esaulpaugh'
 version '1.4.9-SNAPSHOT'
 
 test {
-    maxParallelForks = (int) Runtime.runtime.availableProcessors().intdiv(2) ?: 1
+    maxParallelForks = (int) Runtime.runtime.availableProcessors() ?: 1
 }
 
 task javadocJar(type: Jar, dependsOn: javadoc) {
diff --git a/pom.xml b/pom.xml
index 043a4dd9b..b83a109ef 100644
--- a/pom.xml
+++ b/pom.xml
@@ -102,7 +102,7 @@
                 <configuration>
                     <useSystemClassLoader>false</useSystemClassLoader>
                     <parallel>all</parallel>
-                    <threadCount>2</threadCount>
+                    <threadCount>8</threadCount>
                 </configuration>
             </plugin>
             <plugin>
diff --git a/src/test/java/com/esaulpaugh/headlong/abi/UnsignedTest.java b/src/test/java/com/esaulpaugh/headlong/abi/UnsignedTest.java
index aa640e972..2d0e66a6a 100644
--- a/src/test/java/com/esaulpaugh/headlong/abi/UnsignedTest.java
+++ b/src/test/java/com/esaulpaugh/headlong/abi/UnsignedTest.java
@@ -102,21 +102,27 @@ public void testToSigned() {
     @Test
     public void testUintTypeSymmetry() {
         Random r = new Random(MonteCarloTest.getSeed(System.nanoTime()));
-        Integers.UintType type = new Integers.UintType(64);
-        final long mask = (long) (Math.pow(2, 64) - 1.0d);
-        for (int j = 0; j < 1_000; j++) {
-            long x = pickRandom(r);
-            x &= mask;
-            Assertions.assertEquals(x, type.toSigned(type.toUnsigned(x)));
-            Assertions.assertEquals(x, type.toUnsigned(type.toSigned(x)));
-            BigInteger bigIntX = BigInteger.valueOf(x);
-            Assertions.assertEquals(bigIntX, type.toUnsigned(type.toSigned(bigIntX)));
+        for (int i = 1; i < 64; i++) {
+            Integers.UintType type = new Integers.UintType(i);
+            final long mask = (long) Math.pow(2, i - 1) - 1L;
+            for (int j = 0; j < 25; j++) {
+                long x = pickRandom(r);
+                x &= mask;
+                Assertions.assertEquals(x, type.toSigned(type.toUnsigned(x)));
+                Assertions.assertEquals(x, type.toUnsigned(type.toSigned(x)));
+                BigInteger bigIntX = BigInteger.valueOf(x);
+                Assertions.assertEquals(bigIntX, type.toUnsigned(type.toSigned(bigIntX)));
+                Assertions.assertEquals(bigIntX, type.toSigned(type.toUnsigned(bigIntX)));
+            }
         }
-        for (int j = 0; j < 1_000; j++) {
-            BigInteger x = BigInteger.valueOf(pickRandom(r));
-            Assertions.assertEquals(x, type.toSigned(type.toUnsigned(x)));
-            x = x.abs();
-            Assertions.assertEquals(x, type.toUnsigned(type.toSigned(x)));
+        for (int i = 64; i <= 256; i++) {
+            Integers.UintType type = new Integers.UintType(i);
+            for (int j = 0; j < 25; j++) {
+                BigInteger x = BigInteger.valueOf(pickRandom(r));
+                Assertions.assertEquals(x, type.toSigned(type.toUnsigned(x)));
+                x = x.abs();
+                Assertions.assertEquals(x, type.toUnsigned(type.toSigned(x)));
+            }
         }
     }