diff --git a/python/templates/MutableObject.cc.jinja2 b/python/templates/MutableObject.cc.jinja2
index edbca8da9..bb851a48c 100644
--- a/python/templates/MutableObject.cc.jinja2
+++ b/python/templates/MutableObject.cc.jinja2
@@ -8,7 +8,7 @@
 {{ include }}
 {% endfor %}
 
-#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 #include "nlohmann/json.hpp"
 #endif
 
diff --git a/python/templates/MutableObject.h.jinja2 b/python/templates/MutableObject.h.jinja2
index b34b63a58..649147201 100644
--- a/python/templates/MutableObject.h.jinja2
+++ b/python/templates/MutableObject.h.jinja2
@@ -16,7 +16,7 @@
 #include <ostream>
 #include <cstddef>
 
-#ifdef PODIO_JSON_OUTPUT
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 #include "nlohmann/json_fwd.hpp"
 #endif
 
diff --git a/python/templates/Object.cc.jinja2 b/python/templates/Object.cc.jinja2
index 37414ec52..bbb8e8856 100644
--- a/python/templates/Object.cc.jinja2
+++ b/python/templates/Object.cc.jinja2
@@ -8,7 +8,7 @@
 {{ include }}
 {% endfor %}
 
-#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 #include "nlohmann/json.hpp"
 #endif
 
diff --git a/python/templates/Object.h.jinja2 b/python/templates/Object.h.jinja2
index 1e2562299..926158b5a 100644
--- a/python/templates/Object.h.jinja2
+++ b/python/templates/Object.h.jinja2
@@ -14,7 +14,7 @@
 #include <ostream>
 #include <cstddef>
 
-#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 #include "nlohmann/json_fwd.hpp"
 #endif
 
diff --git a/python/templates/macros/declarations.jinja2 b/python/templates/macros/declarations.jinja2
index a0c976bc4..166b53121 100644
--- a/python/templates/macros/declarations.jinja2
+++ b/python/templates/macros/declarations.jinja2
@@ -134,7 +134,7 @@
 {%- endmacro %}
 
 {% macro json_output(type, prefix='') %}
-#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 void to_json(nlohmann::json& j, const {{ prefix }}{{ type }}& value);
 #endif
 {% endmacro %}
diff --git a/python/templates/macros/implementations.jinja2 b/python/templates/macros/implementations.jinja2
index 0ddb29e39..096a93ae5 100644
--- a/python/templates/macros/implementations.jinja2
+++ b/python/templates/macros/implementations.jinja2
@@ -210,7 +210,7 @@ std::ostream& operator<<(std::ostream& o, const {{ type }}& value) {
 {%- endmacro %}
 
 {% macro json_output(class, members, single_relations, multi_relations, vector_members, get_syntax, prefix='') %}
-#ifdef PODIO_JSON_OUTPUT
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 void to_json(nlohmann::json& j, const {{ prefix }}{{ class.bare_type }}& value) {
   j = nlohmann::json{
 {% set comma = joiner(",") %}