diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7975c0b53..d7b719f61 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## [Unreleased]
 
 ### Added
+* Include optional parameters in spellcheck, if it contains text
 
 ### Fixed
 * Fix LaTeX files not showing up when choosing main file in run configuration
diff --git a/src/nl/hannahsten/texifyidea/completion/LatexBibliographyReferenceProvider.kt b/src/nl/hannahsten/texifyidea/completion/LatexBibliographyReferenceProvider.kt
index 6a4155b5c..3f67e1a02 100644
--- a/src/nl/hannahsten/texifyidea/completion/LatexBibliographyReferenceProvider.kt
+++ b/src/nl/hannahsten/texifyidea/completion/LatexBibliographyReferenceProvider.kt
@@ -51,9 +51,11 @@ object LatexBibliographyReferenceProvider : CompletionProvider<CompletionParamet
         result.withPrefixMatcher(CamelHumpMatcher(prefix, false)).addAllElements(lookupItems + lookupItemsFromRemote)
     }
 
-    private fun createLookupElementFromBibtexEntry(bibtexEntry: BibtexEntry, remote: Boolean = false): LookupElementBuilder {
+    private fun createLookupElementFromBibtexEntry(bibtexEntry: BibtexEntry, remote: Boolean = false): LookupElementBuilder? {
         val lookupStrings = LinkedList(bibtexEntry.getAuthors())
         lookupStrings.add(bibtexEntry.getTitle())
+        // Ensure a consistent project (#3802)
+        if (bibtexEntry.id?.project != bibtexEntry.id?.containingFile?.project) return null
         return LookupElementBuilder.create(bibtexEntry.getIdentifier())
             .withPsiElement(bibtexEntry.id)
             .withPresentableText(bibtexEntry.getTitle())
diff --git a/src/nl/hannahsten/texifyidea/inspections/LatexSpellcheckingStrategy.kt b/src/nl/hannahsten/texifyidea/inspections/LatexSpellcheckingStrategy.kt
index 0a0fdb8e5..925db3d12 100644
--- a/src/nl/hannahsten/texifyidea/inspections/LatexSpellcheckingStrategy.kt
+++ b/src/nl/hannahsten/texifyidea/inspections/LatexSpellcheckingStrategy.kt
@@ -2,14 +2,12 @@ package nl.hannahsten.texifyidea.inspections
 
 import com.intellij.psi.PsiElement
 import com.intellij.psi.impl.source.tree.LeafPsiElement
-import com.intellij.psi.util.PsiTreeUtil
+import com.intellij.psi.util.parentOfType
 import com.intellij.spellchecker.tokenizer.SpellcheckingStrategy
 import com.intellij.spellchecker.tokenizer.Tokenizer
 import nl.hannahsten.texifyidea.grammar.LatexLanguage
-import nl.hannahsten.texifyidea.lang.commands.Argument
+import nl.hannahsten.texifyidea.lang.commands.*
 import nl.hannahsten.texifyidea.lang.commands.Argument.Type
-import nl.hannahsten.texifyidea.lang.commands.LatexMathCommand
-import nl.hannahsten.texifyidea.lang.commands.LatexRegularCommand
 import nl.hannahsten.texifyidea.psi.*
 import nl.hannahsten.texifyidea.util.parser.firstParentOfType
 import nl.hannahsten.texifyidea.util.parser.hasParent
@@ -33,8 +31,7 @@ class LatexSpellcheckingStrategy : SpellcheckingStrategy() {
             psiElement.elementType == LatexTypes.COMMENT_TOKEN ||
             psiElement.elementType == LatexTypes.LEFT ||
             psiElement.elementType == LatexTypes.RIGHT ||
-            isBeginEnd(psiElement) ||
-            psiElement.hasParent(LatexOptionalParam::class)
+            isBeginEnd(psiElement)
         ) {
             return EMPTY_TOKENIZER
         }
@@ -57,30 +54,35 @@ class LatexSpellcheckingStrategy : SpellcheckingStrategy() {
     }
 
     private fun isBeginEnd(element: PsiElement): Boolean {
-        var elt: PsiElement? = PsiTreeUtil.getParentOfType(element, LatexBeginCommand::class.java)
-        if (elt != null) {
-            return true
-        }
-
-        elt = PsiTreeUtil.getParentOfType(element, LatexEndCommand::class.java)
-        return elt != null
+        return element.parentOfType<LatexEndCommand>() != null || element.parentOfType<LatexBeginCommand>() != null
     }
 
     /**
      * Get the argument (with type) from TeXiFy knowledge that corresponds with the current psi element.
      */
     private fun getArgument(leaf: LeafPsiElement): Argument? {
-        val parent = PsiTreeUtil.getParentOfType(leaf, LatexCommands::class.java) ?: return null
+        val parent = leaf.parentOfType<LatexCommands>() ?: return null
 
-        val arguments = getArguments(parent.commandToken.text.substring(1)) ?: return null
+        val arguments = getArguments(parent.name?.substring(1) ?: return null) ?: return null
+        val requiredArguments = arguments.filterIsInstance<RequiredArgument>()
+        val optionalArguments = arguments.filterIsInstance<OptionalArgument>()
 
-        val realParams = parent.getRequiredParameters()
+        val requiredParams = parent.getRequiredParameters()
         // Note that a leaf may be only part of a parameter
-        val parameterIndex = realParams.indexOf(leaf.firstParentOfType(LatexParameterText::class)?.text)
-        return if (parameterIndex < 0 || parameterIndex >= arguments.size) {
+        val parameterText = leaf.firstParentOfType(LatexParameterText::class)?.text
+        val parameterIndex = requiredParams.indexOf(parameterText)
+        if (parameterIndex >= 0 && parameterIndex < requiredArguments.size) {
+            return arguments[parameterIndex]
+        }
+
+        // Also check optional arguments, if not key-value pairs it may contain text
+        val optionalParamIndex = parent.getOptionalParameterMap().map { it.key.text }.indexOf(parameterText)
+        return if (optionalParamIndex >= 0 && optionalParamIndex < optionalArguments.size) {
+            optionalArguments[optionalParamIndex]
+        }
+        else {
             null
         }
-        else arguments[parameterIndex]
     }
 
     private fun getArguments(commandName: String): Array<out Argument>? {
diff --git a/test/nl/hannahsten/texifyidea/inspections/latex/LatexSpellCheckingStrategyTest.kt b/test/nl/hannahsten/texifyidea/inspections/latex/LatexSpellCheckingStrategyTest.kt
index af4a3e571..7f0654f5a 100644
--- a/test/nl/hannahsten/texifyidea/inspections/latex/LatexSpellCheckingStrategyTest.kt
+++ b/test/nl/hannahsten/texifyidea/inspections/latex/LatexSpellCheckingStrategyTest.kt
@@ -17,4 +17,17 @@ class LatexSpellCheckingStrategyTest : TexifyInspectionTestBase(SpellCheckingIns
         )
         myFixture.checkHighlighting()
     }
+
+    fun testOptionalParameterTypo() {
+        myFixture.configureByText(
+            LatexFileType,
+            """
+               \begin{description}
+                  \item[<TYPO descr="Typo: In word 'Tpyo'">Tpyo</TYPO>]
+                   <TYPO descr="Typo: In word 'Tpyo'">Tpyo</TYPO>
+               \end{description}
+            """.trimIndent()
+        )
+        myFixture.checkHighlighting()
+    }
 }
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