diff --git a/src/util/symbol.cpp b/src/util/symbol.cpp
index 73225b1e502..051fabfd39f 100644
--- a/src/util/symbol.cpp
+++ b/src/util/symbol.cpp
@@ -176,3 +176,8 @@ bool symbolt::operator==(const symbolt &other) const
     is_volatile == other.is_volatile;
   // clang-format on
 }
+
+bool symbolt::operator!=(const symbolt &other) const
+{
+  return !(*this == other);
+}
diff --git a/src/util/symbol.h b/src/util/symbol.h
index e0fa8cf446c..45aa4654699 100644
--- a/src/util/symbol.h
+++ b/src/util/symbol.h
@@ -126,6 +126,7 @@ class symbolt
   bool is_well_formed() const;
 
   bool operator==(const symbolt &other) const;
+  bool operator!=(const symbolt &other) const;
 };
 
 std::ostream &operator<<(std::ostream &out, const symbolt &symbol);