diff --git a/src/solvers/strings/string_constraint_generator.h b/src/solvers/strings/string_constraint_generator.h
index f439e5f28b3..01c9d2f119e 100644
--- a/src/solvers/strings/string_constraint_generator.h
+++ b/src/solvers/strings/string_constraint_generator.h
@@ -133,8 +133,6 @@ class string_constraint_generatort final
   std::pair<exprt, string_constraintst>
   add_axioms_for_equals_ignore_case(const function_application_exprt &f);
 
-  std::pair<exprt, string_constraintst>
-  add_axioms_for_is_empty(const function_application_exprt &f);
   std::pair<exprt, string_constraintst> add_axioms_for_is_prefix(
     const array_string_exprt &prefix,
     const array_string_exprt &str,
diff --git a/src/solvers/strings/string_constraint_generator_main.cpp b/src/solvers/strings/string_constraint_generator_main.cpp
index 81603410ed6..aa1904934c5 100644
--- a/src/solvers/strings/string_constraint_generator_main.cpp
+++ b/src/solvers/strings/string_constraint_generator_main.cpp
@@ -225,7 +225,21 @@ string_constraint_generatort::add_axioms_for_function_application(
   else if(id == ID_cprover_string_equals_ignore_case_func)
     return add_axioms_for_equals_ignore_case(expr);
   else if(id == ID_cprover_string_is_empty_func)
-    return add_axioms_for_is_empty(expr);
+  {
+    // Inlined logic from deprecated add_axioms_for_is_empty
+    // Returns true when the string is empty (length == 0)
+    PRECONDITION(expr.type() == bool_typet() || expr.type().id() == ID_c_bool);
+    PRECONDITION(expr.arguments().size() == 1);
+    const array_string_exprt s0 =
+      get_string_expr(array_pool, expr.arguments()[0]);
+    const symbol_exprt is_empty = fresh_symbol("is_empty");
+    string_constraintst constraints;
+    constraints.existential = {
+      implies_exprt(is_empty, equal_to(array_pool.get_or_create_length(s0), 0)),
+      implies_exprt(
+        equal_to(array_pool.get_or_create_length(s0), 0), is_empty)};
+    return {typecast_exprt(is_empty, expr.type()), std::move(constraints)};
+  }
   else if(id == ID_cprover_string_char_at_func)
     return add_axioms_for_char_at(expr);
   else if(id == ID_cprover_string_is_prefix_func)
diff --git a/src/solvers/strings/string_constraint_generator_testing.cpp b/src/solvers/strings/string_constraint_generator_testing.cpp
index 9fab7d39601..0a54cf25d2e 100644
--- a/src/solvers/strings/string_constraint_generator_testing.cpp
+++ b/src/solvers/strings/string_constraint_generator_testing.cpp
@@ -10,11 +10,10 @@ Author: Romain Brenguier, romain.brenguier@diffblue.com
 /// \file
 /// Generates string constraints for string functions that return Boolean values
 
-#include "string_constraint_generator.h"
-
-#include <util/deprecate.h>
 #include <util/mathematical_expr.h>
 
+#include "string_constraint_generator.h"
+
 /// Add axioms stating that the returned expression is true exactly when the
 /// offset is greater or equal to 0 and the first string is a prefix of the
 /// second one, starting at position offset.
@@ -120,31 +119,6 @@ string_constraint_generatort::add_axioms_for_is_prefix(
   return {typecast_exprt(pair.first, f.type()), std::move(pair.second)};
 }
 
-/// Add axioms stating that the returned value is true exactly when the argument
-/// string is empty.
-/// \deprecated should use `string_length(s)==0` instead
-/// \param f: function application with a string argument
-/// \return a Boolean expression
-DEPRECATED(SINCE(2017, 10, 5, "should use `string_length s == 0` instead"))
-std::pair<exprt, string_constraintst>
-string_constraint_generatort::add_axioms_for_is_empty(
-  const function_application_exprt &f)
-{
-  PRECONDITION(f.type() == bool_typet() || f.type().id() == ID_c_bool);
-  PRECONDITION(f.arguments().size() == 1);
-  // We add axioms:
-  // a1 : is_empty => |s0| = 0
-  // a2 : s0 => is_empty
-
-  symbol_exprt is_empty = fresh_symbol("is_empty");
-  array_string_exprt s0 = get_string_expr(array_pool, f.arguments()[0]);
-  string_constraintst constraints;
-  constraints.existential = {
-    implies_exprt(is_empty, equal_to(array_pool.get_or_create_length(s0), 0)),
-    implies_exprt(equal_to(array_pool.get_or_create_length(s0), 0), is_empty)};
-  return {typecast_exprt(is_empty, f.type()), std::move(constraints)};
-}
-
 /// Test if the target is a suffix of the string
 ///
 /// Add axioms ensuring the return value is true when the first string ends with