diff --git a/src/language/node_processor/AffectationProcessor.hpp b/src/language/node_processor/AffectationProcessor.hpp
index c172874b8af2bbd5408832e090ecd14492be7745..c36a747289310b6e1cd393c2a2d437c015e45d50 100644
--- a/src/language/node_processor/AffectationProcessor.hpp
+++ b/src/language/node_processor/AffectationProcessor.hpp
@@ -111,11 +111,11 @@ class AffectationExecutor final : public IAffectationExecutor
           } else {
             if constexpr (std::is_same_v<std::string, DataT>) {
               std::get<std::string>(m_lhs) += std::get<std::string>(rhs);
-            } else if constexpr (std::is_arithmetic_v<DataT>) {
+            } else if constexpr ((std::is_arithmetic_v<DataT>)and not(std::is_same_v<bool, DataT>)) {
               std::get<std::string>(m_lhs) += std::to_string(std::get<DataT>(rhs));
             } else {
               std::ostringstream os;
-              os << std::get<DataT>(rhs);
+              os << std::boolalpha << std::get<DataT>(rhs);
               std::get<std::string>(m_lhs) += os.str();
             }
           }
diff --git a/tests/test_AffectationToStringProcessor.cpp b/tests/test_AffectationToStringProcessor.cpp
index 01c7ba7b938945dc9f929f602a3fe071b052379c..73337da4ca7eb09d1adac3cf1c158787a411f495 100644
--- a/tests/test_AffectationToStringProcessor.cpp
+++ b/tests/test_AffectationToStringProcessor.cpp
@@ -81,8 +81,7 @@ TEST_CASE("ASTAffectationToStringProcessor", "[language]")
     CHECK_AFFECTATION_RESULT(R"(let n : N, n = 2; let s : string, s = "foo"; s += n;)", "s",
                              (std::string("foo") + std::to_string(2ul)));
     CHECK_AFFECTATION_RESULT(R"(let s : string, s = "foo"; s += -1;)", "s", (std::string("foo") + std::to_string(-1l)));
-    CHECK_AFFECTATION_RESULT(R"(let s : string, s = "foo"; s += true;)", "s",
-                             (std::string("foo") + std::to_string(true)));
+    CHECK_AFFECTATION_RESULT(R"(let s : string, s = "foo"; s += true;)", "s", (std::string("footrue")));
     CHECK_AFFECTATION_RESULT(R"(let s : string, s = "foo"; s += 2.3;)", "s",
                              (std::string("foo") + std::to_string(2.3)));
     {