diff --git a/python/psi-api/src/com/jetbrains/python/psi/PyCallExpression.java b/python/psi-api/src/com/jetbrains/python/psi/PyCallExpression.java
index e716edd74955..8c4ea4433e6f 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/PyCallExpression.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/PyCallExpression.java
@@ -374,6 +374,7 @@ public interface PyCallExpression extends PyCallSiteExpression {
   class PyArgumentsMapping {
     @NotNull private final PyCallSiteExpression myCallSiteExpression;
     @Nullable private final PyMarkedCallee myMarkedCallee;
+    @NotNull private final List<PyCallableParameter> myImplicitParameters;
     @NotNull private final Map<PyExpression, PyCallableParameter> myMappedParameters;
     @NotNull private final List<PyCallableParameter> myUnmappedParameters;
     @NotNull private final List<PyExpression> myUnmappedArguments;
@@ -383,6 +384,7 @@ public interface PyCallExpression extends PyCallSiteExpression {
 
     public PyArgumentsMapping(@NotNull PyCallSiteExpression callSiteExpression,
                               @Nullable PyMarkedCallee markedCallee,
+                              @NotNull List<PyCallableParameter> implicitParameters,
                               @NotNull Map<PyExpression, PyCallableParameter> mappedParameters,
                               @NotNull List<PyCallableParameter> unmappedParameters,
                               @NotNull List<PyExpression> unmappedArguments,
@@ -391,6 +393,7 @@ public interface PyCallExpression extends PyCallSiteExpression {
                               @NotNull Map<PyExpression, PyCallableParameter> tupleMappedParameters) {
       myCallSiteExpression = callSiteExpression;
       myMarkedCallee = markedCallee;
+      myImplicitParameters = implicitParameters;
       myMappedParameters = mappedParameters;
       myUnmappedParameters = unmappedParameters;
       myUnmappedArguments = unmappedArguments;
@@ -399,10 +402,29 @@ public interface PyCallExpression extends PyCallSiteExpression {
       myMappedTupleParameters = tupleMappedParameters;
     }
 
+    /**
+     * @deprecated
+     * Use {@link #PyArgumentsMapping(PyCallSiteExpression, PyMarkedCallee, List, Map, List, List, List, List, Map)} that includes
+     * implicitly mapped parameters. This constructor will be removed in 2018.2.
+     */
+    @Deprecated
+    public PyArgumentsMapping(@NotNull PyCallSiteExpression callSiteExpression,
+                              @Nullable PyMarkedCallee markedCallee,
+                              @NotNull Map<PyExpression, PyCallableParameter> mappedParameters,
+                              @NotNull List<PyCallableParameter> unmappedParameters,
+                              @NotNull List<PyExpression> unmappedArguments,
+                              @NotNull List<PyCallableParameter> parametersMappedToVariadicPositionalArguments,
+                              @NotNull List<PyCallableParameter> parametersMappedToVariadicKeywordArguments,
+                              @NotNull Map<PyExpression, PyCallableParameter> tupleMappedParameters) {
+      this(callSiteExpression, markedCallee, Collections.emptyList(), mappedParameters, unmappedParameters, unmappedArguments,
+           parametersMappedToVariadicPositionalArguments, parametersMappedToVariadicKeywordArguments, tupleMappedParameters);
+    }
+
     @NotNull
     public static PyArgumentsMapping empty(@NotNull PyCallSiteExpression callSiteExpression) {
       return new PyCallExpression.PyArgumentsMapping(callSiteExpression,
                                                      null,
+                                                     Collections.emptyList(),
                                                      Collections.emptyMap(),
                                                      Collections.emptyList(),
                                                      Collections.emptyList(),
@@ -421,6 +443,11 @@ public interface PyCallExpression extends PyCallSiteExpression {
       return myMarkedCallee;
     }
 
+    @NotNull
+    public List<PyCallableParameter> getImplicitParameters() {
+      return myImplicitParameters;
+    }
+
     @NotNull
     public Map<PyExpression, PyCallableParameter> getMappedParameters() {
       return myMappedParameters;
diff --git a/python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java b/python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java
index d9d5a3c75a22..27fee7dff030 100644
--- a/python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java
+++ b/python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java
@@ -724,12 +724,15 @@ public class PyCallExpressionHelper {
     final List<PyCallableParameter> parameters = markedCallee.getCallableType().getParameters(context);
     if (parameters == null) return PyCallExpression.PyArgumentsMapping.empty(callExpression);
 
-    final List<PyCallableParameter> explicitParameters = dropImplicitParameters(parameters, markedCallee.getImplicitOffset());
+    final int safeImplicitOffset = Math.min(markedCallee.getImplicitOffset(), parameters.size());
+    final List<PyCallableParameter> explicitParameters = parameters.subList(safeImplicitOffset, parameters.size());
+    final List<PyCallableParameter> implicitParameters = parameters.subList(0, safeImplicitOffset);
     final List<PyExpression> arguments = Arrays.asList(argumentList.getArguments());
     final ArgumentMappingResults mappingResults = analyzeArguments(arguments, explicitParameters);
 
     return new PyCallExpression.PyArgumentsMapping(callExpression,
                                                    markedCallee,
+                                                   implicitParameters,
                                                    mappingResults.getMappedParameters(),
                                                    mappingResults.getUnmappedParameters(),
                                                    mappingResults.getUnmappedArguments(),
@@ -798,26 +801,18 @@ public class PyCallExpressionHelper {
     if (parameters == null) return PyCallExpression.PyArgumentsMapping.empty(callSite);
 
     final List<PyExpression> arguments = callSite.getArguments(callable);
-    final List<PyCallableParameter> explicitParameters =
-      filterExplicitParameters(parameters, callable, callSite, resolveContext);
+    final List<PyCallableParameter> explicitParameters = filterExplicitParameters(parameters, callable, callSite, resolveContext);
+    final List<PyCallableParameter> implicitParameters = parameters.subList(0, parameters.size() - explicitParameters.size());
 
     final ArgumentMappingResults mappingResults = analyzeArguments(arguments, explicitParameters);
-    final Map<PyExpression, PyCallableParameter> mapped = new LinkedHashMap<>();
-    final PyExpression receiver = callSite.getReceiver(callable);
-    if (receiver != null && !explicitParameters.equals(parameters)) {
-      final PyCallableParameter first = ContainerUtil.getFirstItem(parameters);
-      if (first != null && first.getParameter() != null && first.getParameter().isSelf()) {
-        mapped.put(receiver, first);
-      }
-    }
-    mapped.putAll(mappingResults.getMappedParameters());
 
     final PyCallExpression.PyMarkedCallee markedCallee =
       new PyCallExpression.PyMarkedCallee(callableType, callable, null, 0, false, RatedResolveResult.RATE_NORMAL);
 
     return new PyCallExpression.PyArgumentsMapping(callSite,
                                                    markedCallee,
-                                                   mapped,
+                                                   implicitParameters,
+                                                   mappingResults.getMappedParameters(),
                                                    mappingResults.getUnmappedParameters(),
                                                    mappingResults.getUnmappedArguments(),
                                                    mappingResults.getParametersMappedToVariadicPositionalArguments(),
diff --git a/python/src/com/jetbrains/python/psi/impl/PyFunctionImpl.java b/python/src/com/jetbrains/python/psi/impl/PyFunctionImpl.java
index 596ade04a864..f2325c6ce516 100644
--- a/python/src/com/jetbrains/python/psi/impl/PyFunctionImpl.java
+++ b/python/src/com/jetbrains/python/psi/impl/PyFunctionImpl.java
@@ -230,10 +230,17 @@ public class PyFunctionImpl extends PyBaseElementImpl<PyFunctionStub> implements
     }
 
     final PyExpression receiver = callSite.getReceiver(this);
-    final Map<PyExpression, PyCallableParameter> mapping =
-      PyCallExpressionHelper.mapArguments(callSite, this, context).getMappedParameters();
+    final PyCallExpression.PyArgumentsMapping fullMapping = PyCallExpressionHelper.mapArguments(callSite, this, context);
+    final Map<PyExpression, PyCallableParameter> mappedExplicitParameters = fullMapping.getMappedParameters();
 
-    return getCallType(receiver, mapping, context);
+    final Map<PyExpression, PyCallableParameter> allMappedParameters = new LinkedHashMap<>();
+    final PyCallableParameter firstImplicit = ContainerUtil.getFirstItem(fullMapping.getImplicitParameters());
+    if (receiver != null && firstImplicit != null) {
+      allMappedParameters.put(receiver, firstImplicit);
+    }
+    allMappedParameters.putAll(mappedExplicitParameters);
+
+    return getCallType(receiver, allMappedParameters, context);
   }
 
   @Nullable