diff --git a/idea/src/org/jetbrains/kotlin/idea/imports/KotlinImportOptimizer.kt b/idea/src/org/jetbrains/kotlin/idea/imports/KotlinImportOptimizer.kt
index 270c3d707ec..2b718461754 100644
--- a/idea/src/org/jetbrains/kotlin/idea/imports/KotlinImportOptimizer.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/imports/KotlinImportOptimizer.kt
@@ -20,6 +20,7 @@ import com.intellij.lang.ImportOptimizer
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.progress.ProgressIndicatorProvider
 import com.intellij.openapi.util.text.StringUtil
+import com.intellij.psi.PsiDocumentManager
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import org.jetbrains.kotlin.descriptors.*
@@ -60,9 +61,23 @@ class KotlinImportOptimizer : ImportOptimizer {
         }
     }
 
+    // The same as com.intellij.pom.core.impl.PomModelImpl.isDocumentUncommitted
+    // Which is checked in com.intellij.pom.core.impl.PomModelImpl.startTransaction
+    private val KtFile.isDocumentUncommitted: Boolean
+        get() {
+            val documentManager = PsiDocumentManager.getInstance(project)
+            val cachedDocument = documentManager.getCachedDocument(this)
+            return cachedDocument != null && documentManager.isUncommited(cachedDocument)
+        }
+
     private fun prepareImports(file: KtFile): OptimizeInformation? {
         ApplicationManager.getApplication().assertReadAccessAllowed()
 
+        // Optimize imports may be called after command
+        // And document can be uncommitted after running that command
+        // In that case we will get ISE: Attempt to modify PSI for non-committed Document!
+        if (file.isDocumentUncommitted) return null
+
         val moduleInfo = file.getNullableModuleInfo()
         if (moduleInfo !is ModuleSourceInfo && moduleInfo !is ScriptModuleInfo) return null