diff --git a/.phive/phars.xml b/.phive/phars.xml
index 5230620..20a8222 100644
--- a/.phive/phars.xml
+++ b/.phive/phars.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phive xmlns="https://phar.io/phive">
   <phar name="php-cs-fixer" version="^2.16" installed="2.16.4" location="./tools/php-cs-fixer" copy="true"/>
-  <phar name="psalm" version="^3.8" installed="3.18.2" location="./tools/psalm" copy="true"/>
+  <phar name="psalm" version="^4.0" installed="4.0.1" location="./tools/psalm" copy="true"/>
   <phar name="roave/backwardcompatibilitycheck" version="^5.0.0" installed="5.0.0" location="./tools/roave-backward-compatibility-check" copy="true"/>
 </phive>
diff --git a/.psalm/baseline.xml b/.psalm/baseline.xml
index 80cc8e2..bdf9f40 100644
--- a/.psalm/baseline.xml
+++ b/.psalm/baseline.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<files psalm-version="3.16@d03e5ef057d6adc656c0ff7e166c50b73b4f48f3">
+<files psalm-version="4.0.1@b1e2e30026936ef8d5bf6a354d1c3959b6231f44">
   <file src="src/Exporter.php">
     <ConflictingReferenceConstraint occurrences="1">
       <code>if (is_object($value)) {</code>
@@ -11,5 +11,10 @@
       <code>$hash</code>
       <code>$key</code>
     </InvalidScalarArgument>
+    <MissingParamType occurrences="3">
+      <code>$value</code>
+      <code>$value</code>
+      <code>$value</code>
+    </MissingParamType>
   </file>
 </files>
diff --git a/.psalm/config.xml b/.psalm/config.xml
index 5fe4867..06cc040 100644
--- a/.psalm/config.xml
+++ b/.psalm/config.xml
@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
 <psalm
-    totallyTyped="false"
-    cacheDirectory=".psalm/cache"
-    errorBaseline=".psalm/baseline.xml"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="https://getpsalm.org/schema/config"
     xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
+    resolveFromConfigFile="false"
+    cacheDirectory=".psalm/cache"
+    errorBaseline=".psalm/baseline.xml"
+    totallyTyped="false"
 >
     <projectFiles>
         <directory name="src" />
@@ -13,44 +14,4 @@
             <directory name="vendor" />
         </ignoreFiles>
     </projectFiles>
-
-    <issueHandlers>
-        <LessSpecificReturnType errorLevel="info" />
-
-        <!-- level 3 issues - slightly lazy code writing, but provably low false-negatives -->
-
-        <DeprecatedMethod errorLevel="info" />
-        <DeprecatedProperty errorLevel="info" />
-        <DeprecatedClass errorLevel="info" />
-        <DeprecatedConstant errorLevel="info" />
-        <DeprecatedFunction errorLevel="info" />
-        <DeprecatedInterface errorLevel="info" />
-        <DeprecatedTrait errorLevel="info" />
-
-        <InternalMethod errorLevel="info" />
-        <InternalProperty errorLevel="info" />
-        <InternalClass errorLevel="info" />
-
-        <MissingClosureReturnType errorLevel="info" />
-        <MissingReturnType errorLevel="info" />
-        <MissingPropertyType errorLevel="info" />
-        <InvalidDocblock errorLevel="info" />
-        <MisplacedRequiredParam errorLevel="info" />
-
-        <PropertyNotSetInConstructor errorLevel="info" />
-        <MissingConstructor errorLevel="info" />
-        <MissingClosureParamType errorLevel="info" />
-        <MissingParamType errorLevel="info" />
-
-        <RedundantCondition errorLevel="info" />
-
-        <DocblockTypeContradiction errorLevel="info" />
-        <RedundantConditionGivenDocblockType errorLevel="info" />
-
-        <UnresolvableInclude errorLevel="info" />
-
-        <RawObjectIteration errorLevel="info" />
-
-        <InvalidStringClass errorLevel="info" />
-    </issueHandlers>
 </psalm>
diff --git a/tools/psalm b/tools/psalm
index 05b467a..c19205d 100755
Binary files a/tools/psalm and b/tools/psalm differ