diff --git a/unit/Makefile b/unit/Makefile
index 8757d39c42b..eeff4e499fe 100644
--- a/unit/Makefile
+++ b/unit/Makefile
@@ -35,6 +35,7 @@ SRC += unit_tests.cpp \
        util/irep_sharing.cpp \
        util/message.cpp \
        util/optional.cpp \
+       util/replace_symbol.cpp \
        util/sharing_node.cpp \
        util/sharing_map.cpp \
        util/small_map.cpp \
diff --git a/unit/util/replace_symbol.cpp b/unit/util/replace_symbol.cpp
new file mode 100644
index 00000000000..ad5190c8353
--- /dev/null
+++ b/unit/util/replace_symbol.cpp
@@ -0,0 +1,66 @@
+/*******************************************************************\
+
+ Module: replace_symbolt unit tests
+
+ Author: Michael Tautschnig
+
+\*******************************************************************/
+
+#include <testing-utils/catch.hpp>
+
+#include <util/replace_symbol.h>
+#include <util/std_expr.h>
+
+TEST_CASE("Replace all symbols in expression", "[core][util][replace_symbol]")
+{
+  symbol_exprt s1("a", typet("some_type"));
+  symbol_exprt s2("b", typet("some_type"));
+
+  exprt binary("binary", typet("some_type"));
+  binary.copy_to_operands(s1);
+  binary.copy_to_operands(s2);
+
+  array_typet array_type(typet("sub-type"), s1);
+  REQUIRE(array_type.size() == s1);
+
+  exprt other_expr("other");
+
+  replace_symbolt r;
+  r.insert("a", other_expr);
+
+  REQUIRE(r.replace(binary) == false);
+  REQUIRE(binary.op0() == other_expr);
+
+  REQUIRE(r.replace(s1) == false);
+  REQUIRE(s1 == other_expr);
+
+  REQUIRE(r.replace(s2) == true);
+  REQUIRE(s2 == symbol_exprt("b", typet("some_type")));
+
+  REQUIRE(r.replace(array_type) == false);
+  REQUIRE(array_type.size() == other_expr);
+}
+
+TEST_CASE("Lvalue only", "[core][util][replace_symbol]")
+{
+  symbol_exprt s1("a", typet("some_type"));
+  array_typet array_type(typet("some_type"), s1);
+  symbol_exprt array("b", array_type);
+  index_exprt index(array, s1);
+
+  exprt binary("binary", typet("some_type"));
+  binary.copy_to_operands(address_of_exprt(s1));
+  binary.copy_to_operands(address_of_exprt(index));
+
+  constant_exprt c("some_value", typet("some_type"));
+
+  replace_symbolt r;
+  r.insert("a", c);
+
+  REQUIRE(r.replace(binary) == false);
+  REQUIRE(binary.op0() == address_of_exprt(s1));
+  const index_exprt &index_expr =
+    to_index_expr(to_address_of_expr(binary.op1()).object());
+  REQUIRE(to_array_type(index_expr.array().type()).size() == c);
+  REQUIRE(index_expr.index() == c);
+}