diff --git a/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java b/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
index c736720dcbe..d72b9cc3921 100644
--- a/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
+++ b/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
@@ -313,6 +313,12 @@ public class Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated exte
       runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/arrayCompoundAssignementTarget.kt");
     }
 
+    @Test
+    @TestMetadata("augmentedArrayAssigment.kt")
+    public void testAugmentedArrayAssigment() {
+      runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt");
+    }
+
     @Test
     @TestMetadata("readArrayElement.kt")
     public void testReadArrayElement() {
diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirExpressionTypeProvider.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirExpressionTypeProvider.kt
index 44f328d7b2a..f5c4895504b 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirExpressionTypeProvider.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirExpressionTypeProvider.kt
@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getOutermostParenthesizerOrThis
+import org.jetbrains.kotlin.util.OperatorNameConventions
 import org.jetbrains.kotlin.utils.addToStdlib.applyIf
 import org.jetbrains.kotlin.utils.exceptions.rethrowExceptionWithDetails
 import org.jetbrains.kotlin.utils.exceptions.withPsiEntry
@@ -150,7 +151,8 @@ internal class KtFirExpressionTypeProvider(
         expression: KtExpression,
         fir: FirFunctionCall,
     ): KtType? {
-        if (fir.calleeReference !is FirResolvedNamedReference) return null
+        // When we're in a call like `a[x] = y`, we want to get the `set` call's last argument's type.
+        if (fir.calleeReference !is FirResolvedNamedReference || fir.calleeReference.name != OperatorNameConventions.SET) return null
         if (expression !is KtArrayAccessExpression) return null
         val assignment = expression.parent as? KtBinaryExpression ?: return null
         if (assignment.operationToken !in KtTokens.ALL_ASSIGNMENTS) return null
diff --git a/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeDependentAnalysisSourceModuleHLExpressionTypeTestGenerated.java b/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeDependentAnalysisSourceModuleHLExpressionTypeTestGenerated.java
index c3cc45be6d6..cd939cd49a8 100644
--- a/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeDependentAnalysisSourceModuleHLExpressionTypeTestGenerated.java
+++ b/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeDependentAnalysisSourceModuleHLExpressionTypeTestGenerated.java
@@ -313,6 +313,12 @@ public class FirIdeDependentAnalysisSourceModuleHLExpressionTypeTestGenerated ex
       runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/arrayCompoundAssignementTarget.kt");
     }
 
+    @Test
+    @TestMetadata("augmentedArrayAssigment.kt")
+    public void testAugmentedArrayAssigment() {
+      runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt");
+    }
+
     @Test
     @TestMetadata("readArrayElement.kt")
     public void testReadArrayElement() {
diff --git a/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java b/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
index caddf3b733a..edcaae40248 100644
--- a/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
+++ b/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
@@ -313,6 +313,12 @@ public class FirIdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated exten
       runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/arrayCompoundAssignementTarget.kt");
     }
 
+    @Test
+    @TestMetadata("augmentedArrayAssigment.kt")
+    public void testAugmentedArrayAssigment() {
+      runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt");
+    }
+
     @Test
     @TestMetadata("readArrayElement.kt")
     public void testReadArrayElement() {
diff --git a/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/expressionTypeProvider/FirStandaloneNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java b/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/expressionTypeProvider/FirStandaloneNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
index c82a18834b8..6f289bb3411 100644
--- a/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/expressionTypeProvider/FirStandaloneNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
+++ b/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/expressionTypeProvider/FirStandaloneNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java
@@ -313,6 +313,12 @@ public class FirStandaloneNormalAnalysisSourceModuleHLExpressionTypeTestGenerate
       runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/arrayCompoundAssignementTarget.kt");
     }
 
+    @Test
+    @TestMetadata("augmentedArrayAssigment.kt")
+    public void testAugmentedArrayAssigment() {
+      runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt");
+    }
+
     @Test
     @TestMetadata("readArrayElement.kt")
     public void testReadArrayElement() {
diff --git a/analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt b/analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt
new file mode 100644
index 00000000000..46893117421
--- /dev/null
+++ b/analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt
@@ -0,0 +1,8 @@
+operator fun Array<String>.get(index1: Int, index2: Int) = this[index1 + index2]
+operator fun Array<String>.set(index1: Int, index2: Int, elem: String) {
+    this[index1 + index2] = elem
+}
+
+fun test(s: Array<String>) {
+    <expr>s[2, -2]</expr> += "K"
+}
diff --git a/analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.txt b/analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.txt
new file mode 100644
index 00000000000..e611af515d0
--- /dev/null
+++ b/analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.txt
@@ -0,0 +1,2 @@
+expression: s[2, -2]
+type: kotlin.String