diff --git a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/files/FileStructureRule.kt b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/files/FileStructureRule.kt
index 388f2b920b..e02f214e45 100644
--- a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/files/FileStructureRule.kt
+++ b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/files/FileStructureRule.kt
@@ -5,7 +5,6 @@ import org.cqfn.diktat.common.config.rules.RulesConfig
 import org.cqfn.diktat.common.config.rules.getCommonConfiguration
 import org.cqfn.diktat.common.config.rules.getRuleConfig
 import org.cqfn.diktat.ruleset.constants.EmitType
-import org.cqfn.diktat.ruleset.constants.Warnings
 import org.cqfn.diktat.ruleset.constants.Warnings.FILE_CONTAINS_ONLY_COMMENTS
 import org.cqfn.diktat.ruleset.constants.Warnings.FILE_INCORRECT_BLOCKS_ORDER
 import org.cqfn.diktat.ruleset.constants.Warnings.FILE_NO_BLANK_LINE_BETWEEN_BLOCKS
@@ -18,6 +17,7 @@ import org.cqfn.diktat.ruleset.utils.copyrightWords
 import org.cqfn.diktat.ruleset.utils.findAllNodesWithSpecificType
 import org.cqfn.diktat.ruleset.utils.handleIncorrectOrder
 import org.cqfn.diktat.ruleset.utils.moveChildBefore
+import org.cqfn.diktat.ruleset.utils.operatorMap
 
 import com.pinterest.ktlint.core.Rule
 import com.pinterest.ktlint.core.ast.ElementType.BLOCK_COMMENT
@@ -73,12 +73,6 @@ class FileStructureRule(private val configRules: List<RulesConfig>) : Rule("file
         }
     private val refSet: MutableSet<String> = mutableSetOf()
     private var packageName = ""
-    private val operatorMap = mapOf(
-        "unaryPlus" to "+", "unaryMinus" to "-", "not" to "!",
-        "plus" to "+", "minus" to "-", "times" to "*", "div" to "/", "rem" to "%", "mod" to "%", "rangeTo" to "..",
-        "inc" to "++", "dec" to "--", "contains" to "in",
-        "plusAssign" to "+=", "minusAssign" to "-=", "timesAssign" to "*=", "divAssign" to "/=", "modAssign" to "%="
-    )
     private lateinit var emitWarn: EmitType
 
     override fun visit(node: ASTNode,
@@ -94,10 +88,7 @@ class FileStructureRule(private val configRules: List<RulesConfig>) : Rule("file
             val importsGroupingConfig = ImportsGroupingConfig(
                 this.configRules.getRuleConfig(FILE_UNORDERED_IMPORTS)?.configuration ?: emptyMap()
             )
-            val unusedImportConfig = UnusedImportConfig(
-                this.configRules.getRuleConfig(UNUSED_IMPORT)?.configuration ?: emptyMap()
-            )
-            checkUnusedImport(node, unusedImportConfig)
+            checkUnusedImport(node)
             node.findChildByType(IMPORT_LIST)
                 ?.let { checkImportsOrder(it, wildcardImportsConfig, importsGroupingConfig) }
             if (checkFileHasCode(node)) {
@@ -222,8 +213,7 @@ class FileStructureRule(private val configRules: List<RulesConfig>) : Rule("file
 
     @Suppress("UnsafeCallOnNullableType")
     private fun checkUnusedImport(
-        node: ASTNode,
-        unusedImportConfig: UnusedImportConfig
+        node: ASTNode
     ) {
         findAllReferences(node)
         packageName = (node.findChildByType(PACKAGE_DIRECTIVE)?.psi as KtPackageDirective).qualifiedName
@@ -236,35 +226,28 @@ class FileStructureRule(private val configRules: List<RulesConfig>) : Rule("file
                         packageName.isNotEmpty() && importPath.startsWith("$packageName.") &&
                         importPath.substring(packageName.length + 1).indexOf('.') == -1
                 ) {
-                    if (unusedImportConfig.deleteUnusedImport) {
-                        Warnings.UNUSED_IMPORT.warnAndFix(
-                            configRules, emitWarn, isFixMode,
-                            "$importPath - unused import",
-                            node.startOffset, node
-                        ) { ktImportDirective.delete() }
-                    }
-                } else if (importName != null && !refSet.contains(getValueMap(importName)) && !refSet.contains(
+                    // this branch corresponds to imports from the same package
+                    deleteImport(importPath, node, ktImportDirective)
+                } else if (importName != null && !refSet.contains(operatorMap.getOrDefault(importName, null)) && !refSet.contains(
                     importName
                 )
                 ) {
-                    if (unusedImportConfig.deleteUnusedImport) {
-                        Warnings.UNUSED_IMPORT.warnAndFix(
-                            configRules, emitWarn, isFixMode,
-                            "$importPath - unused import",
-                            node.startOffset, node
-                        ) { ktImportDirective.delete() }
-                    }
+                    // this import is not used anywhere
+                    deleteImport(importPath, node, ktImportDirective)
                 }
             }
     }
 
-    private fun getValueMap(key: String): String? {
-        val value: String? = try {
-            operatorMap.getValue(key)
-        } catch (e: NoSuchElementException) {
-            null
-        }
-        return value
+    private fun deleteImport(
+        importPath: String,
+        node: ASTNode,
+        ktImportDirective: KtImportDirective
+    ) {
+        UNUSED_IMPORT.warnAndFix(
+            configRules, emitWarn, isFixMode,
+            "$importPath - unused import",
+            node.startOffset, node
+        ) { ktImportDirective.delete() }
     }
 
     private fun findAllReferences(node: ASTNode) {
@@ -390,14 +373,4 @@ class FileStructureRule(private val configRules: List<RulesConfig>) : Rule("file
          */
         val useRecommendedImportsOrder = config["useRecommendedImportsOrder"]?.toBoolean() ?: true
     }
-
-    /**
-     * [RuleConfiguration] for unused import
-     */
-    class UnusedImportConfig(config: Map<String, String>) : RuleConfiguration(config) {
-        /**
-         * delete unused import
-         */
-        val deleteUnusedImport = config["deleteUnusedImport"]?.toBoolean() ?: true
-    }
 }
diff --git a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/AstConstants.kt b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/AstConstants.kt
index 89293a430a..dd52e901d3 100644
--- a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/AstConstants.kt
+++ b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/AstConstants.kt
@@ -42,3 +42,10 @@ enum class StandardPlatforms(val packages: List<String>) {
     KOTLIN(listOf("kotlin", "kotlinx")),
     ;
 }
+
+internal val operatorMap = mapOf(
+    "unaryPlus" to "+", "unaryMinus" to "-", "not" to "!",
+    "plus" to "+", "minus" to "-", "times" to "*", "div" to "/", "rem" to "%", "mod" to "%", "rangeTo" to "..",
+    "inc" to "++", "dec" to "--", "contains" to "in",
+    "plusAssign" to "+=", "minusAssign" to "-=", "timesAssign" to "*=", "divAssign" to "/=", "modAssign" to "%="
+)