diff --git a/lib/coffeescript/lexer.js b/lib/coffeescript/lexer.js
index 50a214faec..d9882df30e 100644
--- a/lib/coffeescript/lexer.js
+++ b/lib/coffeescript/lexer.js
@@ -587,12 +587,16 @@
     // Keeps track of the level of indentation, because a single outdent token
     // can close multiple indents, so we need to know how far in we happen to be.
     lineToken(chunk = this.chunk) {
-      var diff, indent, match, minLiteralLength, newIndentLiteral, noNewlines, size;
+      var backslash, diff, indent, match, minLiteralLength, newIndentLiteral, noNewlines, prev, size;
       if (!(match = MULTI_DENT.exec(chunk))) {
         return 0;
       }
       indent = match[0];
-      this.seenFor = false;
+      prev = this.prev();
+      backslash = (prev != null) && prev[0] === '\\';
+      if (!(backslash && this.seenFor)) {
+        this.seenFor = false;
+      }
       if (!this.importSpecifierList) {
         this.seenImport = false;
       }
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 6e70762d61..b0f4cff7ca 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -449,7 +449,9 @@ exports.Lexer = class Lexer
     return 0 unless match = MULTI_DENT.exec chunk
     indent = match[0]
 
-    @seenFor = no
+    prev = @prev()
+    backslash = prev? and prev[0] is '\\'
+    @seenFor = no unless backslash and @seenFor
     @seenImport = no unless @importSpecifierList
     @seenExport = no unless @exportSpecifierList
 
diff --git a/test/control_flow.coffee b/test/control_flow.coffee
index 22837e8ceb..2825ffa1f7 100644
--- a/test/control_flow.coffee
+++ b/test/control_flow.coffee
@@ -515,3 +515,118 @@ test "#3441: `StatementLiteral` in parentheses", ->
 
   r9 = for a in arr then (a; continue)
   arrayEq r9, []
+
+# Issue #3909: backslash to break line in `for` loops throw syntax error
+test "#3909: backslash `for own ... of`", ->
+
+  obj = {a: 1, b: 2, c: 3}
+  arr = ['a', 'b', 'c']
+
+  x1 \
+    = ( key for own key of obj )
+  arrayEq x1, arr
+
+  x2 = \
+    ( key for own key of obj )
+  arrayEq x2, arr
+
+  x3 = ( \
+    key for own key of obj )
+  arrayEq x3, arr
+
+  x4 = ( key \
+    for own key of obj )
+  arrayEq x4, arr
+
+  x5 = ( key for own key of \
+    obj )
+  arrayEq x5, arr
+
+  x6 = ( key for own key of obj \
+    )
+  arrayEq x6, arr
+
+  x7 = ( key for \
+    own key of obj )
+  arrayEq x7, arr
+
+  x8 = ( key for own \
+    key of obj )
+  arrayEq x8, arr
+
+  x9 = ( key for own key \
+    of obj )
+  arrayEq x9, arr
+
+
+test "#3909: backslash `for ... of`", ->
+  obj = {a: 1, b: 2, c: 3}
+  arr = ['a', 'b', 'c']
+
+  x1 \
+    = ( key for key of obj )
+  arrayEq x1, arr
+
+  x2 = \
+    ( key for key of obj )
+  arrayEq x2, arr
+
+  x3 = ( \
+    key for key of obj )
+  arrayEq x3, arr
+
+  x4 = ( key \
+    for key of obj )
+  arrayEq x4, arr
+
+  x5 = ( key for key of \
+    obj )
+  arrayEq x5, arr
+
+  x6 = ( key for key of obj \
+    )
+  arrayEq x6, arr
+
+  x7 = ( key for \
+    key of obj )
+  arrayEq x7, arr
+
+  x8 = ( key for key \
+    of obj )
+  arrayEq x8, arr
+
+
+test "#3909: backslash `for ... in`", ->
+  arr = ['a', 'b', 'c']
+
+  x1 \
+    = ( key for key in arr )
+  arrayEq x1, arr
+
+  x2 = \
+    ( key for key in arr )
+  arrayEq x2, arr
+
+  x3 = ( \
+    key for key in arr )
+  arrayEq x3, arr
+
+  x4 = ( key \
+    for key in arr )
+  arrayEq x4, arr
+
+  x5 = ( key for key in \
+    arr )
+  arrayEq x5, arr
+
+  x6 = ( key for key in arr \
+    )
+  arrayEq x6, arr
+
+  x7 = ( key for \
+    key in arr )
+  arrayEq x7, arr
+
+  x8 = ( key for key \
+    in arr )
+  arrayEq x8, arr