diff --git a/pmd/etc/changelog.txt b/pmd/etc/changelog.txt
index 4315ebfc40..e1b36fb3e4 100644
--- a/pmd/etc/changelog.txt
+++ b/pmd/etc/changelog.txt
@@ -25,6 +25,7 @@ Fixed bug 1445231 - TestClassWithoutTestCases: no longer flags abstract classes.
 Fixed bug 1445765 - PMD no longer uses huge amounts of memory.  However, you need to use RuleViolation.getBeginLine(); RuleViolation.getNode() is no more.
 Fixed bug 1447295 - UseNotifyAllInsteadOfNotify no longer flags notify() methods that have a parameter. 
 Implemented RFE 1415487 - Added a rulesets/releases/35.xml ruleset (and similar rulesets for previous releases) contains rules new to PMD v3.5
+Wouter Zelle fixed a false positive in NonThreadSafeSingleton.
 Fixed bug in CallSuperInConstructor; it no longer flag classes without extends clauses.
 Fixed release packaging; now entire xslt/ directory contents are included.
 Added more XSLT from Dave Corley - you can use them to filter PMD reports by priority level.
diff --git a/pmd/rulesets/design.xml b/pmd/rulesets/design.xml
index 00d5bee15e..37ac9c1975 100644
--- a/pmd/rulesets/design.xml
+++ b/pmd/rulesets/design.xml
@@ -1125,14 +1125,16 @@ See Effective Java, item 48.
             <property name="xpath">
                 <value><![CDATA[
 //MethodDeclaration[$checkNonStaticMethods='true' or @Static='true'][@Synchronized='false']
-//IfStatement[not (ancestor::SynchronizedStatement)]/Expression
- /EqualityExpression
+//IfStatement[not (ancestor::SynchronizedStatement)]
+ [Expression/EqualityExpression
    [PrimaryExpression/PrimaryPrefix/Literal/NullLiteral]
-   [PrimaryExpression/PrimaryPrefix
-     /Name[@Image=
+   [PrimaryExpression/PrimaryPrefix/Name[@Image=
        //FieldDeclaration[$checkNonStaticFields='true' or @Static='true']
-       /VariableDeclarator/VariableDeclaratorId/@Image]
-]
+       /VariableDeclarator/VariableDeclaratorId/@Image]]]
+ [Statement//StatementExpression[AssignmentOperator]
+       [PrimaryExpression/PrimaryPrefix/Name/@Image=
+        ancestor::ClassOrInterfaceBody//FieldDeclaration[$checkNonStaticFields='true' or @Static='true']
+   /VariableDeclarator/VariableDeclaratorId/@Image]]
                 ]]></value>
             </property>
             <property name="checkNonStaticMethods">
diff --git a/pmd/xdocs/credits.xml b/pmd/xdocs/credits.xml
index e15bc101c6..78b958e86c 100644
--- a/pmd/xdocs/credits.xml
+++ b/pmd/xdocs/credits.xml
@@ -48,10 +48,10 @@
         </subsection>
         <subsection name="Contributors">
         <ul>
+            <li>Wouter Zelle - Fixed a false positive in NonThreadSafeSingleton, a nice patch to clean up some of the Ant task properties and fix a TextRenderer bug, rewrote PositionLiteralsFirstInComparisons in XPath, Renderer improvement suggestions, wrote NonThreadSafeSingleton rule, wrote DefaultPackage rule, worked thru ASTMethodDeclaration.isSyntacticallyX design, reported docs bug 1292689 for UnnecessaryLocalBeforeReturn, reported leftover ExceptionTypeChecking source file, rewrote UselessOverridingMethod in Java, UselessOverridingMethod rule, ProperLogger rule, nifty code to allow variables in XPath rules, externalInfoUrl data for all rules in basic and unusedcode rulesets, some very nifty XSLT, improvements to UseCorrectExceptionLogging, designed and implemented the "externalInfoUrl" feature in the rule definitions, fixed a devious bug in RuleSetFactory, AvoidPrintStackTrace, initial implementation of SimplifyConditional</li>
             <li>Uroshnor - Reported bug in UseNotifyAllInsteadOfNotify</li>
             <li>Jan Koops - Noted missing data in MemberValuePair nodes, bug report for JBuilder plugin</li>
             <li>Christopher Stach - several bug reports for rules that didn't handle JDK 1.5 enums</li>
-            <li>Wouter Zelle - A nice patch to clean up some of the Ant task properties and fix a TextRenderer bug, rewrote PositionLiteralsFirstInComparisons in XPath, Renderer improvement suggestions, wrote NonThreadSafeSingleton rule, wrote DefaultPackage rule, worked thru ASTMethodDeclaration.isSyntacticallyX design, reported docs bug 1292689 for UnnecessaryLocalBeforeReturn, reported leftover ExceptionTypeChecking source file, rewrote UselessOverridingMethod in Java, UselessOverridingMethod rule, ProperLogger rule, nifty code to allow variables in XPath rules, externalInfoUrl data for all rules in basic and unusedcode rulesets, some very nifty XSLT, improvements to UseCorrectExceptionLogging, designed and implemented the "externalInfoUrl" feature in the rule definitions, fixed a devious bug in RuleSetFactory, AvoidPrintStackTrace, initial implementation of SimplifyConditional</li>
             <li>Xavier Le Vourch - SimplifyBooleanAssertion, patch to fix problem with TestClassWithoutTestCases, patch to fix rule name bugs in migration rulesets</li>
             <li><a href="http://tersesystems.com/">Will Sargent</a> - Implemented AvoidThreadGroup, AvoidThrowingCertainExceptionTypesRule, AvoidCatchingNPERule, ExceptionAsFlowControlRule, URL updates for 'Similar projects' page</li>
             <li>Benoit Xhenseval - noted Maven plugin bug (http://jira.codehaus.org/browse/MPPMD-24), bug report for UnusedPrivateMethod, suggestion to add elapsed time to XML report, bug report for ImmutableField, many bug reports (with good failure cases!), Ant task patch and bug report, XSLT patch, suggestion for improving XML report</li>