diff --git a/AUTHORS b/AUTHORS
index 2e9eb5a..755bfd4 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -40,6 +40,7 @@
 Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
 Riku Voipio <riku.voipio@linaro.org>
 Saikrishna Arcot <saiarcot895@gmail.com>
+Stephan Hartmann <stha09@googlemail.com>
 Tim Niederhausen <tim@rnc-ag.de>
 Tomas Popela <tomas.popela@gmail.com>
 Tripta Gupta <tripta.g@samsung.com>
diff --git a/src/gn/err.h b/src/gn/err.h
index 6bd2f02..f9a7d76 100644
--- a/src/gn/err.h
+++ b/src/gn/err.h
@@ -59,6 +59,8 @@
 
   ~Err();
 
+  Err& operator=(const Err&) = default;
+
   bool has_error() const { return has_error_; }
   const Location& location() const { return location_; }
   const std::string& message() const { return message_; }
diff --git a/src/gn/label_pattern.h b/src/gn/label_pattern.h
index fbb11fa..7444ae2 100644
--- a/src/gn/label_pattern.h
+++ b/src/gn/label_pattern.h
@@ -35,6 +35,8 @@
   LabelPattern(const LabelPattern& other);
   ~LabelPattern();
 
+  LabelPattern& operator=(const LabelPattern&) = default;
+
   // Converts the given input string to a pattern. This does special stuff
   // to treat the pattern as a label. Sets the error on failure.
   static LabelPattern GetPattern(const SourceDir& current_dir,
diff --git a/src/gn/substitution_list.h b/src/gn/substitution_list.h
index c1985bb..559b25d 100644
--- a/src/gn/substitution_list.h
+++ b/src/gn/substitution_list.h
@@ -17,6 +17,8 @@
   SubstitutionList(const SubstitutionList& other);
   ~SubstitutionList();
 
+  SubstitutionList& operator=(const SubstitutionList&) = default;
+
   bool Parse(const Value& value, Err* err);
   bool Parse(const std::vector<std::string>& values,
              const ParseNode* origin,
diff --git a/src/gn/substitution_pattern.h b/src/gn/substitution_pattern.h
index f6ad22e..48f4eb7 100644
--- a/src/gn/substitution_pattern.h
+++ b/src/gn/substitution_pattern.h
@@ -37,6 +37,8 @@
   SubstitutionPattern(const SubstitutionPattern& other);
   ~SubstitutionPattern();
 
+  SubstitutionPattern& operator=(const SubstitutionPattern&) = default;
+
   // Parses the given string and fills in the pattern. The pattern must only
   // be initialized once. On failure, returns false and sets the error.
   bool Parse(const Value& value, Err* err);