diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/KotlinNameSuggester.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/KotlinNameSuggester.kt
index 61813f73574..af78d37f708 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/KotlinNameSuggester.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/KotlinNameSuggester.kt
@@ -105,6 +105,7 @@ object KotlinNameSuggester {
     }
 
     private val COMMON_TYPE_PARAMETER_NAMES = listOf("T", "U", "V", "W", "X", "Y", "Z")
+    private val MAX_NUMBER_OF_SUGGESTED_NAME_CHECKS = 1000
 
     fun suggestNamesForTypeParameters(count: Int, validator: (String) -> Boolean): List<String> {
         val result = ArrayList<String>()
@@ -143,7 +144,7 @@ object KotlinNameSuggester {
     fun suggestNameByName(name: String, validator: (String) -> Boolean): String {
         if (validator(name)) return name
         var i = 1
-        while (!validator(name + i)) {
+        while (i <= MAX_NUMBER_OF_SUGGESTED_NAME_CHECKS && !validator(name + i)) {
             ++i
         }
 
diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/NameValidators.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/NameValidators.kt
index 24ef1cfc8e6..5e8f7379769 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/NameValidators.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/NameValidators.kt
@@ -37,6 +37,7 @@ import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.resolve.scopes.LexicalScope
 import org.jetbrains.kotlin.resolve.scopes.utils.findClassifier
 import org.jetbrains.kotlin.resolve.source.getPsi
+import org.jetbrains.kotlin.types.ErrorUtils
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 import java.util.*
 
@@ -94,7 +95,7 @@ class NewDeclarationNameValidator(
         }
     }
 
-    private fun notExcluded(it: DeclarationDescriptorWithSource) = it.source.getPsi() !in excludedDeclarations
+    private fun isExcluded(it: DeclarationDescriptorWithSource) = ErrorUtils.isError(it) || it.source.getPsi() in excludedDeclarations
 
     private fun LexicalScope.hasConflict(name: Name): Boolean {
         fun DeclarationDescriptor.isVisible(): Boolean {
@@ -106,10 +107,10 @@ class NewDeclarationNameValidator(
 
         return when(target) {
             Target.VARIABLES ->
-                getAllAccessibleVariables(name).any { !it.isExtension && it.isVisible() && notExcluded(it) }
+                getAllAccessibleVariables(name).any { !it.isExtension && it.isVisible() && !isExcluded(it) }
             Target.FUNCTIONS_AND_CLASSES ->
-                getAllAccessibleFunctions(name).any { !it.isExtension && it.isVisible() && notExcluded(it) } ||
-                findClassifier(name, NoLookupLocation.FROM_IDE)?.let { it.isVisible() && notExcluded(it) } ?: false
+                getAllAccessibleFunctions(name).any { !it.isExtension && it.isVisible() && !isExcluded(it) } ||
+                findClassifier(name, NoLookupLocation.FROM_IDE)?.let { it.isVisible() && !isExcluded(it) } ?: false
         }
     }