diff --git a/src/dfmt/formatter.d b/src/dfmt/formatter.d
index d351285..669f3a3 100644
--- a/src/dfmt/formatter.d
+++ b/src/dfmt/formatter.d
@@ -763,7 +763,7 @@ private:
             formatAt();
             break;
         case tok!"!":
-            if (peekIs(tok!"is") && !peekBackIsOneOf(false, tok!"(", tok!"="))
+            if ((peekIs(tok!"is") || peekIs(tok!"in")) && !peekBackIsOneOf(false, tok!"(", tok!"="))
                 write(" ");
             goto case;
         case tok!"...":
diff --git a/tests/allman/issue0136.d.ref b/tests/allman/issue0136.d.ref
new file mode 100644
index 0000000..c5d8941
--- /dev/null
+++ b/tests/allman/issue0136.d.ref
@@ -0,0 +1,4 @@
+unittest
+{
+    auto result = name !in aa;
+}
diff --git a/tests/issue0136.d b/tests/issue0136.d
new file mode 100644
index 0000000..076bab8
--- /dev/null
+++ b/tests/issue0136.d
@@ -0,0 +1,4 @@
+unittest
+{
+	auto result = name !in aa;
+}
diff --git a/tests/otbs/issue0136.d.ref b/tests/otbs/issue0136.d.ref
new file mode 100644
index 0000000..9f04038
--- /dev/null
+++ b/tests/otbs/issue0136.d.ref
@@ -0,0 +1,3 @@
+unittest {
+    auto result = name !in aa;
+}