diff --git a/CHANGES.current b/CHANGES.current
index d87daeec6..ce8efe1bf 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -7,6 +7,12 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.1.0 (in progress)
 ===========================
 
+2022-03-08: olly
+	    #1006 SWIG now copes with an interface filename specified on the
+	    command line which contains a closing parenthesis `)`, and more
+	    generally with attributes to `%include` and `%import` which
+	    are quoted and contain parentheses.
+
 2022-03-07: Omar Medina
 	    [Tcl] https://sourceforge.net/p/swig/bugs/1290/
 	    Fix SWIG_AsWCharPtrAndSize() to actually assign to result
diff --git a/Examples/test-suite/import_nomodule.i b/Examples/test-suite/import_nomodule.i
index 48e119517..2794ad5f3 100644
--- a/Examples/test-suite/import_nomodule.i
+++ b/Examples/test-suite/import_nomodule.i
@@ -6,7 +6,9 @@
 // For Python
 %warnfilter(SWIGWARN_TYPE_UNDEFINED_CLASS) Bar; // Base class 'Foo' ignored - unknown module name for base. Either import the appropriate module interface file or specify the name of the module in the %import directive. 
 
-%import "import_nomodule.h"
+// The "dummy=" attribute is a regression test for #1006, fixed in SWIG 4.1.0.
+// SWIG didn't used to take quoting into account when finding the closing `)`.
+%import(dummy=")foo\"") "import_nomodule.h"
 
 #if !defined(SWIGJAVA) && !defined(SWIGRUBY) && !defined(SWIGCSHARP) && !defined(SWIGD) && !defined(SWIGPYTHON_BUILTIN) && !defined(SWIGPHP)
 
diff --git a/Source/Preprocessor/cpp.c b/Source/Preprocessor/cpp.c
index 439788b4b..34ace2d77 100644
--- a/Source/Preprocessor/cpp.c
+++ b/Source/Preprocessor/cpp.c
@@ -741,14 +741,35 @@ static String *get_options(String *str) {
     opt = NewString("(");
     while (((c = Getc(str)) != EOF)) {
       Putc(c, opt);
-      if (c == ')') {
-	level--;
-	if (!level)
-	  return opt;
+      switch (c) {
+	case ')':
+	  level--;
+	  if (!level)
+	    return opt;
+	  break;
+	case '(':
+	  level++;
+	  break;
+	case '"':
+	  /* Skip over quoted strings */
+	  while (1) {
+	    c = Getc(str);
+	    if (c == EOF)
+	      goto bad;
+	    Putc(c, opt);
+	    if (c == '"')
+	      break;
+	    if (c == '\\') {
+	      c = Getc(str);
+	      if (c == EOF)
+		goto bad;
+	      Putc(c, opt);
+	    }
+	  }
+	  break;
       }
-      if (c == '(')
-	level++;
     }
+bad:
     Delete(opt);
     return 0;
   } else {