diff --git a/python/src/com/jetbrains/python/inspections/PyStringFormatInspection.java b/python/src/com/jetbrains/python/inspections/PyStringFormatInspection.java
index 2d27e6787958..e7e3a3fb84ff 100644
--- a/python/src/com/jetbrains/python/inspections/PyStringFormatInspection.java
+++ b/python/src/com/jetbrains/python/inspections/PyStringFormatInspection.java
@@ -277,39 +277,49 @@ public class PyStringFormatInspection extends PyInspection {
             return 0;
           }
         }
+        int referenceKeyNumber = 0;
         for (PyKeyValueExpression expression : expressions) {
           final PyExpression key = expression.getKey();
+          final PyExpression value = expression.getValue();
           if (key instanceof PyStringLiteralExpression) {
-            final String name = ((PyStringLiteralExpression)key).getStringValue();
-            if (myUsedMappingKeys.get(name) != null) {
-              myUsedMappingKeys.put(name, true);
-              final PyExpression value = expression.getValue();
-              if (value != null) {
-                checkExpressionType(value, myFormatSpec.get(name), problemTarget);
-              }
-            }
+            resolveMappingKey(problemTarget, (PyStringLiteralExpression)key, value);
+          }
+          else if (key instanceof PyReferenceExpression) {
+            referenceKeyNumber ++;
           }
         }
         for (Map.Entry<PyExpression, PyExpression> expression : additionalExpressions.entrySet()) {
           final PyExpression key = expression.getKey();
+          final PyExpression value = expression.getValue();
           if (key instanceof PyStringLiteralExpression) {
-            final String name = ((PyStringLiteralExpression)key).getStringValue();
-            if (myUsedMappingKeys.get(name) != null) {
-              myUsedMappingKeys.put(name, true);
-              final PyExpression value = expression.getValue();
-              if (value != null) {
-                checkExpressionType(value, myFormatSpec.get(name), problemTarget);
-              }
+            resolveMappingKey(problemTarget, (PyStringLiteralExpression)key, value);
+          }
+          else if (key instanceof PyReferenceExpression) {
+            referenceKeyNumber ++;
+          }
+        }
+        
+        int unresolved = 0;
+        for (String key : myUsedMappingKeys.keySet()) {
+          if (!myUsedMappingKeys.get(key).booleanValue()) {
+            unresolved++;
+            if (unresolved > referenceKeyNumber) {
+              registerProblem(problemTarget, PyBundle.message("INSP.key.$0.has.no.arg", key));
+              break;
             }
           }
         }
-        for (String key : myUsedMappingKeys.keySet()) {
-          if (!myUsedMappingKeys.get(key).booleanValue()) {
-            registerProblem(problemTarget, PyBundle.message("INSP.key.$0.has.no.arg", key));
-            break;
+        return (expressions.length + additionalExpressions.size());
+      }
+
+      private void resolveMappingKey(PsiElement problemTarget, PyStringLiteralExpression key, PyExpression value) {
+        final String name = key.getStringValue();
+        if (myUsedMappingKeys.get(name) != null) {
+          myUsedMappingKeys.put(name, true);
+          if (value != null) {
+            checkExpressionType(value, myFormatSpec.get(name), problemTarget);
           }
         }
-        return (expressions.length + additionalExpressions.size());
       }
 
       private void registerProblem(@NotNull PsiElement problemTarget, @NotNull final String message, @NotNull LocalQuickFix quickFix) {
diff --git a/python/testData/inspections/PyStringFormatInspection/DictionaryArgument.py b/python/testData/inspections/PyStringFormatInspection/DictionaryArgument.py
index 432540418308..b0caa8f13267 100644
--- a/python/testData/inspections/PyStringFormatInspection/DictionaryArgument.py
+++ b/python/testData/inspections/PyStringFormatInspection/DictionaryArgument.py
@@ -10,3 +10,10 @@ my_dict['tmp'] = 'classes %(claz)s' % <warning descr="Key 'claz' has no followin
 
 
 "%s" % {"a": 1}
+
+f = "fst"
+s = "snd"
+"first is %(fst)s, second is %(snd)s" % {f: 1, s: 2}
+
+snd = "snd"
+"%(f)s %(snd)s" % {"f": 2, snd: 2}
\ No newline at end of file