diff --git a/README.md b/README.md
index 767d9f7..3f4b137 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ Semver sem1 = new Semver("1.2.3-beta.4+sha899d8g79f87"); // Defaults to STRICT m
 Semver sem2 = new Semver("1.2.3-beta.4+sha899d8g79f87", SemverType.NPM); // Specify the mode
 ```
 
-If the version is invalid, a `SemverException` will be thrown.  
+If the version is invalid, a `SemverException` will be thrown.
 You can access the different parts of the version using `getMajor()`, `getMinor()`, `getPatch()`, `getSuffixTokens()` or `getBuild()`.
 
 | Type      | Mandatory           | Optional                    |
@@ -130,6 +130,7 @@ sem.diff("1.2.3-beta.4+sha32iddfu987"); // BUILD
 
 If you want to check if a version satisfies a requirement, use the `satisfies` method.
 
+- A `SemverException` is thrown if the version is not fully-qualified (containing major, minor, and patch versions).
 - In `STRICT` and `LOOSE` modes, the requirement can only be another version.
 - In `NPM` mode, the requirement follows [NPM versioning rules](https://github.com/npm/node-semver).
 
@@ -180,5 +181,5 @@ You can also use built-in versioning methods such as:
 
 ## Contributing
 
-Any pull request or bug report is welcome!  
+Any pull request or bug report is welcome!
 If you have any suggestion about new features, you can open an issue.
diff --git a/pom.xml b/pom.xml
index b39fd49..bbb73b3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -2,19 +2,19 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
-    <groupId>com.vdurmont</groupId>
+    <groupId>org.thshsh</groupId>
     <artifactId>semver4j</artifactId>
-    <version>3.1.0</version>
+    <version>3.1.1</version>
     <packaging>jar</packaging>
 
     <name>semver4j</name>
-    <url>https://github.com/vdurmont/semver4j</url>
+    <url>https://github.com/theshoeshiner/semver4j</url>
     <description>Semantic versioning for Java apps.</description>
 
     <scm>
-        <connection>scm:git:git@github.com:vdurmont/semver4j.git</connection>
-        <developerConnection>scm:git:git@github.com:vdurmont/semver4j.git</developerConnection>
-        <url>git@github.com:vdurmont/semver4j.git</url>
+        <connection>scm:git:git@github.com:theshoeshiner/semver4j.git</connection>
+        <developerConnection>scm:git:git@github.com:theshoeshiner/semver4j.git</developerConnection>
+        <url>git@github.com:theshoeshiner/semver4j.git</url>
     </scm>
 
     <developers>
@@ -23,6 +23,10 @@
             <email>vdurmont@gmail.com</email>
             <url>http://www.vdurmont.com</url>
         </developer>
+        <developer>
+			<name>The Shoe Shiner</name>
+			<email>theshoeshiner@thshsh.org</email>
+		</developer>
     </developers>
 
     <licenses>
@@ -129,6 +133,11 @@
                                 <goals>
                                     <goal>sign</goal>
                                 </goals>
+                                <configuration>
+									<excludes>
+										<exclude>*.asc</exclude>
+									</excludes>
+								</configuration>
                             </execution>
                         </executions>
                     </plugin>
diff --git a/src/main/java/com/vdurmont/semver4j/Requirement.java b/src/main/java/com/vdurmont/semver4j/Requirement.java
index 5a813c4..77f1dd8 100644
--- a/src/main/java/com/vdurmont/semver4j/Requirement.java
+++ b/src/main/java/com/vdurmont/semver4j/Requirement.java
@@ -322,7 +322,8 @@ private static Requirement evaluateReversePolishNotation(Iterator<Tokenizer.Toke
             if (token.type == Tokenizer.TokenType.VERSION) {
                 if ("*".equals(token.value) || (type == Semver.SemverType.NPM && "latest".equals(token.value))) {
                     // Special case for "*" and "latest" in NPM
-                    return new Requirement(new Range("0.0.0", Range.RangeOperator.GTE), null, null, null);
+                    Range range = new Range(new Semver("0.0.0", type), Range.RangeOperator.GTE);
+                    return new Requirement(range, null, null, null);
                 }
                 Semver version = new Semver(token.value, type);
                 if (version.getMinor() != null && version.getPatch() != null) {
@@ -364,7 +365,8 @@ private static Requirement evaluateReversePolishNotation(Iterator<Tokenizer.Toke
                         throw new SemverException("Invalid requirement");
                 }
 
-                Range range = new Range(token2.value, rangeOp);
+                Semver version = new Semver(token2.value, type);
+                Range range = new Range(version, rangeOp);
                 return new Requirement(range, null, null, null);
             } else {
                 // They don't call it "reverse" for nothing
@@ -535,6 +537,21 @@ private static Semver extrapolateVersion(Semver semver) {
         return new Semver(sb.toString(), semver.getType());
     }
 
+    /**
+     * @return Semver type
+     */
+    public Semver.SemverType getType() {
+        if (this.range != null) {
+            return this.range.version.getType();
+        } else if (this.req1 != null) {
+            return this.req1.getType();
+        } else if (this.req2 != null) {
+            return this.req2.getType();
+        } else {
+            return Semver.SemverType.STRICT;
+        }
+    }
+
     /**
      * @see #isSatisfiedBy(Semver)
      *
@@ -543,11 +560,7 @@ private static Semver extrapolateVersion(Semver semver) {
      * @return true if the version satisfies the requirement
      */
     public boolean isSatisfiedBy(String version) {
-        if (this.range != null) {
-            return this.isSatisfiedBy(new Semver(version, this.range.version.getType()));
-        } else {
-            return this.isSatisfiedBy(new Semver(version));
-        }
+        return this.isSatisfiedBy(new Semver(version, this.getType()));
     }
 
     /**
@@ -558,8 +571,18 @@ public boolean isSatisfiedBy(String version) {
      * @return true if the version satisfies the requirement
      */
     public boolean isSatisfiedBy(Semver version) {
+        if (version.getMinor() == null) {
+            throw new SemverException("Invalid version for requirement check (no minor version): " + version.getValue());
+        } else if (version.getPatch() == null) {
+            throw new SemverException("Invalid version for requirement check (no patch version): " + version.getValue());
+        }
+
         if (this.range != null) {
             // We are on a leaf
+            if (version.isPreRelease() && !this.range.version.isPreRelease()) {
+                // Disqualify pre-releases if this is not a pre-release range
+                return false;
+            }
             return this.range.isSatisfiedBy(version);
         } else {
             // We have several sub-requirements
diff --git a/src/main/java/com/vdurmont/semver4j/Semver.java b/src/main/java/com/vdurmont/semver4j/Semver.java
index 1b72a34..d374fdc 100644
--- a/src/main/java/com/vdurmont/semver4j/Semver.java
+++ b/src/main/java/com/vdurmont/semver4j/Semver.java
@@ -1,5 +1,6 @@
 package com.vdurmont.semver4j;
 
+import java.util.Arrays;
 import java.util.Objects;
 
 /**
@@ -178,6 +179,15 @@ public boolean satisfies(String requirement) {
         return this.satisfies(req);
     }
 
+    /**
+     * Checks whether the version is a pre-release
+     *
+     * @return true if the current version is a prerelease
+     */
+    public boolean isPreRelease() {
+        return suffixTokens.length > 0;
+    }
+
     /**
      * @see #isGreaterThan(Semver)
      *
@@ -329,8 +339,22 @@ public boolean isEquivalentTo(String version) {
      */
     public boolean isEquivalentTo(Semver version) {
         // Get versions without build
-        Semver sem1 = this.getBuild() == null ? this : new Semver(this.getValue().replace("+" + this.getBuild(), ""));
-        Semver sem2 = version.getBuild() == null ? version : new Semver(version.getValue().replace("+" + version.getBuild(), ""));
+        Semver sem1 = this.getBuild() == null ? this : new Semver(this.getValue().replace("+" + this.getBuild(), ""), this.getType());
+        Semver sem2 = version.getBuild() == null ? version : new Semver(version.getValue().replace("+" + version.getBuild(), ""), version.getType());
+
+        // Ignore minor and/or patch when versions are not equally qualified
+        if (sem1.getType() != SemverType.STRICT) {
+            if (!sem1.areSameSuffixes(sem2.getSuffixTokens())) return false;
+
+            if (!Objects.equals(sem1.getMajor(), sem2.getMajor())) return false;
+
+            if (sem2.getMinor() == null) return true;
+            if (!Objects.equals(sem1.getMinor(), sem2.getMinor())) return false;
+
+            if (sem2.getPatch() == null) return true;
+            if (!Objects.equals(sem1.getPatch(), sem2.getPatch())) return false;
+        }
+
         // Compare those new versions
         return sem1.isEqualTo(sem2);
     }
@@ -354,12 +378,6 @@ public boolean isEqualTo(String version) {
      * @return true if the current version equals the provided version
      */
     public boolean isEqualTo(Semver version) {
-        if (this.type == SemverType.NPM) {
-            if (this.getMajor() != version.getMajor()) return false;
-            if (version.getMinor() == null) return true;
-            if (version.getPatch() == null) return true;
-        }
-
         return this.equals(version);
     }
 
@@ -442,6 +460,24 @@ public Semver withIncPatch() {
     public Semver withIncPatch(int increment) {
         return this.withInc(0, 0, increment);
     }
+    
+    public Semver withIncSuffix(int index) {
+    	return withIncSuffix(index, 1);
+    }
+
+    public Semver withIncSuffix(int index, int increment) {
+    	if(suffixTokens.length <= index) throw new SemverException("No suffix at index "+index);
+    	try {
+    		Integer token = Integer.valueOf(suffixTokens[index]);
+    		token+=increment;
+    		String[] newSuffix = Arrays.copyOf(suffixTokens,suffixTokens.length);
+    		newSuffix[index] = token.toString();
+    		return with(major,minor,patch,newSuffix,build);
+    	}
+    	catch(NumberFormatException nfe) {
+    		throw new SemverException("Suffix was not integer at index "+index);
+    	}
+    }
 
     private Semver withInc(int majorInc, int minorInc, int patchInc) {
         Integer minor = this.minor;
@@ -542,7 +578,7 @@ private static Semver create(SemverType type, int major, Integer minor, Integer
 
     @Override public int compareTo(Semver version) {
         if (this.isGreaterThan(version)) return 1;
-        else if(this.isLowerThan(version)) return -1;
+        else if (this.isLowerThan(version)) return -1;
         return 0;
     }
 
diff --git a/src/test/java/com/vdurmont/semver4j/NpmSemverTest.java b/src/test/java/com/vdurmont/semver4j/NpmSemverTest.java
index 16ad6ad..a284eef 100644
--- a/src/test/java/com/vdurmont/semver4j/NpmSemverTest.java
+++ b/src/test/java/com/vdurmont/semver4j/NpmSemverTest.java
@@ -30,9 +30,12 @@ public static Iterable<Object[]> getParameters() {
             // Fully-qualified versions:
             { "1.2.3", "1.2.3", true, },
             { "1.2.4", "1.2.3", false, },
+            { "1.3.3", "1.2.3", false, },
+            { "2.2.3", "1.2.3", false, },
 
             // Minor versions:
             { "1.2.3", "1.2", true, },
+            { "1.3.3", "1.2", false, },
             { "1.2.4", "1.3", false, },
 
             // Major versions:
@@ -47,7 +50,7 @@ public static Iterable<Object[]> getParameters() {
             { "2.3.0-alpha", "1.2.3 - 2.3.0-beta", true, },
             { "2.3.4", "1.2.3 - 2.3", true, },
             { "2.3.4", "1.2.3 - 2", true, },
-            { "4.4", "3.X - 4.X", true, },
+            { "4.4.0", "3.X - 4.X", true, },
             { "1.0.0", "1.2.3 - 2.3.4", false, },
             { "3.0.0", "1.2.3 - 2.3.4", false, },
             { "2.4.3", "1.2.3 - 2.3", false, },
@@ -58,7 +61,7 @@ public static Iterable<Object[]> getParameters() {
             { "3.1.5", "", true, },
             { "3.1.5", "*", true, },
             { "0.0.0", "*", true, },
-            { "1.0.0-beta", "*", true, },
+            { "1.0.0-beta", "*", false, },
             { "3.1.5-beta", "3.1.x", false, },
             { "3.1.5-beta+exp.sha.5114f85", "3.1.x", false, },
             { "3.1.5+exp.sha.5114f85", "3.1.x", true, },
@@ -121,6 +124,8 @@ public static Iterable<Object[]> getParameters() {
             { "2.0.1", "=2.0", true, },
             { "2.0.0", "=2", true, },
             { "2.0.1", "=2", true, },
+            { "3.0.0", "=2.0", false, },
+            { "2.1.0", "=2.0", false, },
             { "2.0.1", "=2.0.0", false, },
             { "1.9.9", "=2.0.0", false, },
             { "1.9.9", "=2.0", false, },
@@ -176,6 +181,56 @@ public static Iterable<Object[]> getParameters() {
             { "3.0.0", "<=2.0", false, },
             { "3.0.0", "<=2", false, },
 
+            // Prerelease versions:
+            { "2.0.0-alpha", "=2.0.0-beta", false, },
+            { "2.0.0-rc.2", "=2.0.0-rc.2", true, },
+            { "2.0.0-rc.2", "=2.0.0-rc.3", false, },
+            { "2.0.0-rc.2", "=2.0.0-rc.2.3", false, },
+            { "2.0.0-rc.2", "=2.0.0-rc.3.2", false, },
+            { "2.0.0-rc.2", "=2.0.0", false, },
+            { "2.0.0-rc.2", "=2.0", false, },
+            { "2.0.0-rc.2", "=2", false, },
+
+            { "2.0.0-alpha", ">2.0.0-beta", false, },
+            { "2.0.0-rc.2", ">2.0.0-rc.1", true, },
+            { "2.0.0-rc.2", ">2.0.0-rc.2", false, },
+            { "2.0.0-rc.2", ">2.0.0-rc.3", false, },
+            { "2.0.0-rc.2", ">2.0.0-rc.2.3", false, },
+            { "2.0.0-rc.2", ">2.0.0-rc.3.2", false, },
+            { "2.0.0-rc.2", ">2.0.0", false, },
+            { "2.0.0-rc.2", ">2.0", false, },
+            { "2.0.0-rc.2", ">2", false, },
+
+            { "2.0.0-alpha", "<2.0.0-beta", true, },
+            { "2.0.0-rc.2", "<2.0.0-rc.3", true, },
+            { "2.0.0-rc.2", "<2.0.0-rc.2.3", true, },
+            { "2.0.0-rc.2", "<2.0.0-rc.3.2", true, },
+            { "2.0.0-rc.2", "<2.0.0-rc.1", false, },
+            { "2.0.0-rc.2", "<2.0.0-rc.2", false, },
+            { "2.0.0-rc.2", "<2.0.0", false, },
+            { "2.0.0-rc.2", "<2.0", false, },
+            { "2.0.0-rc.2", "<2", false, },
+
+            { "2.0.0-alpha", ">=2.0.0-beta", false, },
+            { "2.0.0-rc.2", ">=2.0.0-rc.1", true, },
+            { "2.0.0-rc.2", ">=2.0.0-rc.2", true, },
+            { "2.0.0-rc.2", ">=2.0.0-rc.3", false, },
+            { "2.0.0-rc.2", ">=2.0.0-rc.2.3", false, },
+            { "2.0.0-rc.2", ">=2.0.0-rc.3.2", false, },
+            { "2.0.0-rc.2", ">=2.0.0", false, },
+            { "2.0.0-rc.2", ">=2.0", false, },
+            { "2.0.0-rc.2", ">=2", false, },
+
+            { "2.0.0-alpha", "<=2.0.0-beta", true, },
+            { "2.0.0-rc.2", "<=2.0.0-rc.2", true, },
+            { "2.0.0-rc.2", "<=2.0.0-rc.3", true, },
+            { "2.0.0-rc.2", "<=2.0.0-rc.2.3", true, },
+            { "2.0.0-rc.2", "<=2.0.0-rc.3.2", true, },
+            { "2.0.0-rc.2", "<=2.0.0-rc.1", false, },
+            { "2.0.0-rc.2", "<=2.0.0", false, },
+            { "2.0.0-rc.2", "<=2.0", false, },
+            { "2.0.0-rc.2", "<=2", false, },
+
             // AND ranges:
             { "2.0.1", ">2.0.0 <3.0.0", true, },
             { "2.0.1", ">2.0 <3.0", false, },
@@ -222,12 +277,22 @@ public static Iterable<Object[]> getParameters() {
             { "1.1.0", "1.2 <1.2.8 || >2.0.0", false, },
             { "1.2.9", "1.2 <1.2.8 || >2.0.0", false, },
             { "2.0.0", "1.2 <1.2.8 || >2.0.0", false, },
+
+            // Big number equality:
+            { "128.0.0", "=128.0.0", true, },
+            { "127.127.127", "=127.128", false, },
+            { "0.128.0", "=0.128.0", true, },
+            { "0.0.128", "=0.0.128", true, },
+            { "127.127.127", "=127.127.127", true, },
+            { "128.128.128", "=128.128.128", true, },
+            { "999.999.999", "=999.999.999", true, },
+            { "9999.9999.9999", "=9999.9999.9999", true, },
         });
     }
 
     @Test
     public void test() {
-        assertEquals(this.version + " , " + this.rangeExpression ,this.expected, new Semver(this.version, SemverType.NPM).satisfies(this.rangeExpression));
+        assertEquals(this.version + " , " + this.rangeExpression, this.expected, new Semver(this.version, SemverType.NPM).satisfies(this.rangeExpression));
     }
 
 }
diff --git a/src/test/java/com/vdurmont/semver4j/RequirementTest.java b/src/test/java/com/vdurmont/semver4j/RequirementTest.java
index ba9b7e6..55b4ed2 100644
--- a/src/test/java/com/vdurmont/semver4j/RequirementTest.java
+++ b/src/test/java/com/vdurmont/semver4j/RequirementTest.java
@@ -10,6 +10,7 @@
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyZeroInteractions;
@@ -324,9 +325,9 @@ public class RequirementTest {
     @Test public void isSatisfiedBy_with_a_loose_type() {
         Requirement req = Requirement.buildLoose("1.3.2");
 
-        assertFalse(req.isSatisfiedBy("0.27"));
+        assertFalse(req.isSatisfiedBy("0.27.0"));
         assertTrue(req.isSatisfiedBy("1.3.2"));
-        assertFalse(req.isSatisfiedBy("1.5"));
+        assertFalse(req.isSatisfiedBy("1.5.0"));
     }
 
     @Test public void isSatisfiedBy_with_a_complex_example() {
@@ -422,6 +423,14 @@ public class RequirementTest {
         assertTrue(req.isSatisfiedBy("0.2.3"));
     }
 
+    @Test public void isSatisfiedBy_unqualified_exception() {
+        Requirement req = Requirement.buildNPM("1.0");
+        try {
+            req.isSatisfiedBy("1.0");
+            fail("isSatisfiedBy() did not throw as expected.");
+        } catch (SemverException e) {}
+    }
+
     @Test public void tildeRequirement_cocoapods() {
         // '~> 0.1.2' Version 0.1.2 and the versions up to 0.2, not including 0.2 and higher
         tildeTest("0.1.2", "0.1.2", "0.2.0", Semver.SemverType.COCOAPODS);
diff --git a/src/test/java/com/vdurmont/semver4j/SemverTest.java b/src/test/java/com/vdurmont/semver4j/SemverTest.java
index d0c0111..044d366 100644
--- a/src/test/java/com/vdurmont/semver4j/SemverTest.java
+++ b/src/test/java/com/vdurmont/semver4j/SemverTest.java
@@ -13,6 +13,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 
@@ -119,6 +120,15 @@ private static void assertIsSemver(Semver semver, String value, Integer major, I
         assertEquals(build, semver.getBuild());
     }
 
+    @Test public void satisfies_unqualified_exception() {
+        String version = "1.0";
+        Semver semver = new Semver(version, Semver.SemverType.LOOSE);
+        try {
+            semver.satisfies("1.0");
+            fail("satisfies() did not throw as expected.");
+        } catch (SemverException e) {}
+    }
+
     @Test public void statisfies_works_will_all_the_types() {
         // Used to prevent bugs when we add a new type
         for (Semver.SemverType type : Semver.SemverType.values()) {
@@ -187,6 +197,27 @@ private static void assertIsSemver(Semver semver, String value, Integer major, I
         assertTrue(semver.isEquivalentTo(version2));
     }
 
+    @Test public void isEquivalentTo_isEqualTo_without_patch() {
+        Semver semver = new Semver("1.2.3", Semver.SemverType.NPM);
+        String version2 = "1.2";
+        assertFalse(semver.isEqualTo(version2));
+        assertTrue(semver.isEquivalentTo(version2));
+    }
+
+    @Test public void isEqualTo_symmetric() {
+        Semver semver1 = new Semver("1.2.3", Semver.SemverType.NPM);
+        Semver semver2 = new Semver("1.2", Semver.SemverType.NPM);
+        assertFalse(semver1.isEqualTo(semver2));
+        assertFalse(semver2.isEqualTo(semver1));
+    }
+
+    @Test public void isEquivalentTo_asymmetric() {
+        Semver semver1 = new Semver("1.2.3", Semver.SemverType.NPM);
+        Semver semver2 = new Semver("1.2", Semver.SemverType.NPM);
+        assertTrue(semver1.isEquivalentTo(semver2));
+        assertFalse(semver2.isEquivalentTo(semver1));
+    }
+
     @Test public void statisfies_calls_the_requirement() {
         Requirement req = mock(Requirement.class);
         Semver semver = new Semver("1.2.2");
@@ -275,6 +306,40 @@ private static void assertIsSemver(Semver semver, String value, Integer major, I
         Semver semver = new Semver("1.2.3-beta.4+sha123456789");
         semver.nextPatch().isEqualTo("1.2.4");
     }
+    
+    @Test public void withIncSuffix_test() {
+    	Semver semver = new Semver("1.2.3-Draft.1");
+    	Semver result = semver.withIncSuffix(1);
+    	assertEquals("1.2.3-Draft.2", result.toString());
+    }
+    
+    @Test public void withIncSuffix_test_reverse() {
+    	Semver semver = new Semver("1.2.3-1.draft.2");
+    	Semver result = semver.withIncSuffix(0);
+    	assertEquals("1.2.3-2.draft.2", result.toString());
+    }
+    
+    @Test public void withIncSuffix_test_multiple() {
+    	Semver semver = new Semver("1.2.3-1.2");
+    	Semver result = semver.withIncSuffix(1).withIncSuffix(0);
+    	assertEquals("1.2.3-2.3", result.toString());
+    }
+    
+    @Test public void withIncSuffix_test_increment() {
+    	Semver semver = new Semver("1.2.3-draft.1");
+    	Semver result = semver.withIncSuffix(1,3);
+    	assertEquals("1.2.3-draft.4", result.toString());
+    }
+    
+    @Test(expected = SemverException.class) public void withIncSuffix_test_indexerror() {
+    	Semver semver = new Semver("1.2.3-Draft.1");
+    	semver.withIncSuffix(2);
+    }
+    
+    @Test(expected = SemverException.class) public void withIncSuffix_test_formaterror() {
+    	Semver semver = new Semver("1.2.3-Draft.B");
+    	semver.withIncSuffix(1);
+    }
 
     @Test public void toStrict_test() {
         String[][] versionGroups = new String[][]{