diff --git a/idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt b/idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt
index 14cd79751e3..4f605dfafc3 100644
--- a/idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt
+++ b/idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt
@@ -167,6 +167,7 @@ fun createSpacingBuilder(settings: CodeStyleSettings, builderUtil: KotlinSpacing
 
             around(AS_KEYWORD).spaces(1)
             around(IS_KEYWORD).spaces(1)
+            around(IN_KEYWORD).spaces(1)
             aroundInside(IDENTIFIER, BINARY_EXPRESSION).spaces(1)
 
             // before LPAR in constructor(): this() {}
diff --git a/idea/testData/formatter/In.after.kt b/idea/testData/formatter/In.after.kt
new file mode 100644
index 00000000000..c38b491421f
--- /dev/null
+++ b/idea/testData/formatter/In.after.kt
@@ -0,0 +1,5 @@
+fun f() {
+    if (1 in intArrayOf()) {
+
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/formatter/In.kt b/idea/testData/formatter/In.kt
new file mode 100644
index 00000000000..ef7a15b3713
--- /dev/null
+++ b/idea/testData/formatter/In.kt
@@ -0,0 +1,5 @@
+fun f() {
+    if (1   in   intArrayOf()) {
+
+    }
+}
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java b/idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java
index 15b76c7deb6..2683264cb24 100644
--- a/idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java
@@ -349,6 +349,12 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
             doTest(fileName);
         }
 
+        @TestMetadata("In.after.kt")
+        public void testIn() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/In.after.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("InfixCall.after.kt")
         public void testInfixCall() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/InfixCall.after.kt");