diff --git a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleImplicitContributor.java b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleImplicitContributor.java
index cf9a5fc90768..4a917ad70443 100644
--- a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleImplicitContributor.java
+++ b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleImplicitContributor.java
@@ -32,6 +32,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.blocks.GrClosableBlo
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpression;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.path.GrMethodCallExpression;
 import org.jetbrains.plugins.groovy.lang.psi.impl.GroovyPsiManager;
+import org.jetbrains.plugins.groovy.lang.psi.impl.statements.expressions.TypesUtil;
 import org.jetbrains.plugins.groovy.lang.psi.impl.synthetic.GrLightMethodBuilder;
 import org.jetbrains.plugins.groovy.lang.psi.util.GroovyPropertyUtils;
 
@@ -120,7 +121,7 @@ public class GradleImplicitContributor implements GradleMethodContextContributor
         if (psiType != null) {
           final GroovyPsiManager psiManager = GroovyPsiManager.getInstance(place.getProject());
           GradleResolverUtil.processDeclarations(
-            psiManager, processor, state, place, psiType.getCanonicalText());
+            psiManager, processor, state, place, TypesUtil.getQualifiedName(psiType));
         }
       }
     }
diff --git a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleResolverUtil.java b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleResolverUtil.java
index cf7474b35744..cbe6a60279c0 100644
--- a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleResolverUtil.java
+++ b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleResolverUtil.java
@@ -198,6 +198,7 @@ public class GradleResolverUtil {
                                          @NotNull PsiElement place,
                                          @NotNull String... fqNames) {
     for (String fqName : fqNames) {
+      if(fqName == null) continue;
       PsiClass psiClass = psiManager.findClassWithCache(fqName, place.getResolveScope());
       if (psiClass != null) {
         psiClass.processDeclarations(processor, state, null, place);
diff --git a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleTaskContributor.java b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleTaskContributor.java
index f0c4e74b4dc6..050e754776e8 100644
--- a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleTaskContributor.java
+++ b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleTaskContributor.java
@@ -21,16 +21,15 @@ import com.intellij.psi.impl.source.PsiImmediateClassType;
 import com.intellij.psi.scope.PsiScopeProcessor;
 import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.plugins.groovy.lang.parser.GroovyElementTypes;
 import org.jetbrains.plugins.groovy.lang.psi.GroovyPsiElement;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.arguments.GrArgumentList;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.arguments.GrNamedArgument;
-import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrBinaryExpression;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrCommandArgumentList;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpression;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrMethodCall;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.path.GrMethodCallExpression;
 import org.jetbrains.plugins.groovy.lang.psi.impl.GroovyPsiManager;
+import org.jetbrains.plugins.groovy.lang.psi.impl.statements.expressions.TypesUtil;
 import org.jetbrains.plugins.groovy.lang.psi.impl.synthetic.GrLightMethodBuilder;
 import org.jetbrains.plugins.groovy.lang.psi.impl.synthetic.GrLightParameter;
 
@@ -99,7 +98,7 @@ public class GradleTaskContributor implements GradleMethodContextContributor {
               PsiImmediateClassType immediateClassType = (PsiImmediateClassType)psiType;
               for (PsiType type : immediateClassType.getParameters()) {
                 GroovyPsiManager psiManager = GroovyPsiManager.getInstance(place.getProject());
-                GradleResolverUtil.processDeclarations(methodCall, psiManager, processor, state, place, type.getCanonicalText());
+                GradleResolverUtil.processDeclarations(methodCall, psiManager, processor, state, place, TypesUtil.getQualifiedName(type));
               }
             }
           }
diff --git a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleUnresolvedReferenceFilter.java b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleUnresolvedReferenceFilter.java
index 3f2084a6083f..4aff47d4b5a3 100644
--- a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleUnresolvedReferenceFilter.java
+++ b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/GradleUnresolvedReferenceFilter.java
@@ -19,6 +19,7 @@ import com.intellij.psi.PsiType;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.extensions.GroovyUnresolvedHighlightFilter;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrReferenceExpression;
+import org.jetbrains.plugins.groovy.lang.psi.impl.statements.expressions.TypesUtil;
 
 import java.util.Set;
 
@@ -38,6 +39,6 @@ public class GradleUnresolvedReferenceFilter extends GroovyUnresolvedHighlightFi
   @Override
   public boolean isReject(@NotNull GrReferenceExpression expression) {
     final PsiType psiType = GradleResolverUtil.getTypeOf(expression);
-    return psiType != null && IGNORE_SET.contains(psiType.getCanonicalText());
+    return psiType != null && IGNORE_SET.contains(TypesUtil.getQualifiedName(psiType));
   }
 }
diff --git a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/NamedDomainObjectCollectionTypeEnhancer.java b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/NamedDomainObjectCollectionTypeEnhancer.java
index 0180eb6e482a..11b1a3e25b85 100644
--- a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/NamedDomainObjectCollectionTypeEnhancer.java
+++ b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/NamedDomainObjectCollectionTypeEnhancer.java
@@ -24,6 +24,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpres
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrMethodCall;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrReferenceExpression;
 import org.jetbrains.plugins.groovy.lang.psi.impl.GroovyPsiManager;
+import org.jetbrains.plugins.groovy.lang.psi.impl.statements.expressions.TypesUtil;
 import org.jetbrains.plugins.groovy.lang.psi.typeEnhancers.GrReferenceTypeEnhancer;
 
 /**
@@ -68,7 +69,7 @@ public class NamedDomainObjectCollectionTypeEnhancer extends GrReferenceTypeEnha
 
     if (namedDomainCollectionType instanceof PsiClassReferenceType) {
       final PsiClassReferenceType referenceType = (PsiClassReferenceType)namedDomainCollectionType;
-      final String fqName = referenceType.getCanonicalText();
+      final String fqName = TypesUtil.getQualifiedName(referenceType);
       if (GradleCommonClassNames.GRADLE_API_SOURCE_SET_CONTAINER.equals(fqName)) {
         final GroovyPsiManager psiManager = GroovyPsiManager.getInstance(ref.getProject());
         return psiManager.createTypeByFQClassName(GradleCommonClassNames.GRADLE_API_SOURCE_SET, ref.getResolveScope());
diff --git a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/dsl/GradleDslAnnotator.java b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/dsl/GradleDslAnnotator.java
index afa46a709f91..2248b69a02c3 100644
--- a/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/dsl/GradleDslAnnotator.java
+++ b/plugins/gradle/src/org/jetbrains/plugins/gradle/service/resolve/dsl/GradleDslAnnotator.java
@@ -27,6 +27,7 @@ import org.jetbrains.plugins.gradle.service.resolve.GradleResolverUtil;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpression;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrReferenceExpression;
 import org.jetbrains.plugins.groovy.lang.psi.impl.GroovyPsiManager;
+import org.jetbrains.plugins.groovy.lang.psi.impl.statements.expressions.TypesUtil;
 import org.jetbrains.plugins.groovy.lang.psi.util.GroovyCommonClassNames;
 import org.jetbrains.plugins.groovy.lang.resolve.ResolveUtil;
 
@@ -54,7 +55,9 @@ public class GradleDslAnnotator implements Annotator {
           psiManager.findClassWithCache(GroovyCommonClassNames.DEFAULT_GROOVY_METHODS, element.getResolveScope());
         if (canBeMethodOf(referenceExpression.getReferenceName(), defaultGroovyMethodsClass)) return;
 
-        PsiClass containerClass = psiManager.findClassWithCache(psiType.getCanonicalText(), element.getResolveScope());
+        final String qualifiedName = TypesUtil.getQualifiedName(psiType);
+        final PsiClass containerClass =
+          qualifiedName != null ? psiManager.findClassWithCache(qualifiedName, element.getResolveScope()) : null;
         if (canBeMethodOf(referenceExpression.getReferenceName(), containerClass)) return;
 
         PsiElement nameElement = referenceExpression.getReferenceNameElement();