diff --git a/python/src/com/jetbrains/python/parsing/ExpressionParsing.java b/python/src/com/jetbrains/python/parsing/ExpressionParsing.java
index 4742164e08d4..fd009bdefb0a 100644
--- a/python/src/com/jetbrains/python/parsing/ExpressionParsing.java
+++ b/python/src/com/jetbrains/python/parsing/ExpressionParsing.java
@@ -141,7 +141,9 @@ public class ExpressionParsing extends Parsing {
       parseComprehensionRange();
       while (myBuilder.getTokenType() == PyTokenTypes.IF_KEYWORD) {
         myBuilder.advanceLexer();
-        parseOldExpression();
+        if (!parseOldExpression()) {
+          myBuilder.error(message("PARSE.expected.expression"));
+        }
       }
       if (atToken(endToken)) {
         if (leaveEndTokenOutside) {
diff --git a/python/testData/psi/ComprehensionErrors.py b/python/testData/psi/ComprehensionErrors.py
new file mode 100644
index 000000000000..340f4338993c
--- /dev/null
+++ b/python/testData/psi/ComprehensionErrors.py
@@ -0,0 +1 @@
+[for in if]
diff --git a/python/testData/psi/ComprehensionErrors.txt b/python/testData/psi/ComprehensionErrors.txt
new file mode 100644
index 000000000000..f7b9daa48ad7
--- /dev/null
+++ b/python/testData/psi/ComprehensionErrors.txt
@@ -0,0 +1,18 @@
+PyFile:ComprehensionErrors.py
+  PyExpressionStatement
+    PyListCompExpression
+      PsiElement(Py:LBRACKET)('[')
+      PsiErrorElement:expression expected
+        <empty list>
+      PsiElement(Py:FOR_KEYWORD)('for')
+      PsiErrorElement:expression expected
+        <empty list>
+      PsiWhiteSpace(' ')
+      PsiElement(Py:IN_KEYWORD)('in')
+      PsiErrorElement:expression expected
+        <empty list>
+      PsiWhiteSpace(' ')
+      PsiElement(Py:IF_KEYWORD)('if')
+      PsiErrorElement:expression expected
+        <empty list>
+      PsiElement(Py:RBRACKET)(']')
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/PythonParsingTest.java b/python/testSrc/com/jetbrains/python/PythonParsingTest.java
index d47015273c22..c2fa80fa7408 100644
--- a/python/testSrc/com/jetbrains/python/PythonParsingTest.java
+++ b/python/testSrc/com/jetbrains/python/PythonParsingTest.java
@@ -333,6 +333,11 @@ public class PythonParsingTest extends ParsingTestCase {
     doTest(LanguageLevel.PYTHON30);
   }
 
+  // PY-6781
+  public void testComprehensionErrors() {
+    doTest();
+  }
+
   public void doTest() {
     doTest(LanguageLevel.PYTHON25);
   }