diff --git a/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/identifier.h b/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/identifier.h
index bb9dbba7..c1ca9430 100644
--- a/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/identifier.h
+++ b/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/identifier.h
@@ -17,7 +17,7 @@
 
 #include "rosidl_typesupport_opensplice_c/visibility_control.h"
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C"
 {
 #endif
@@ -25,7 +25,7 @@ extern "C"
 ROSIDL_TYPESUPPORT_OPENSPLICE_C_IMPORT
 extern const char * rosidl_typesupport_opensplice_c__identifier;
 
-#if __cplusplus
+#ifdef __cplusplus
 }
 #endif
 
diff --git a/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/visibility_control.h b/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/visibility_control.h
index 71ac1fb2..fbc91d72 100644
--- a/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/visibility_control.h
+++ b/rosidl_typesupport_opensplice_c/include/rosidl_typesupport_opensplice_c/visibility_control.h
@@ -15,7 +15,7 @@
 #ifndef ROSIDL_TYPESUPPORT_OPENSPLICE_C__VISIBILITY_CONTROL_H_
 #define ROSIDL_TYPESUPPORT_OPENSPLICE_C__VISIBILITY_CONTROL_H_
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C"
 {
 #endif
@@ -49,7 +49,7 @@ extern "C"
   #endif
 #endif
 
-#if __cplusplus
+#ifdef __cplusplus
 }
 #endif
 
diff --git a/rosidl_typesupport_opensplice_c/resource/rosidl_typesupport_opensplice_c__visibility_control.h.in b/rosidl_typesupport_opensplice_c/resource/rosidl_typesupport_opensplice_c__visibility_control.h.in
index 0d0fef30..75b13797 100644
--- a/rosidl_typesupport_opensplice_c/resource/rosidl_typesupport_opensplice_c__visibility_control.h.in
+++ b/rosidl_typesupport_opensplice_c/resource/rosidl_typesupport_opensplice_c__visibility_control.h.in
@@ -5,7 +5,7 @@
 #ifndef @PROJECT_NAME_UPPER@__MSG__ROSIDL_TYPESUPPORT_OPENSPLICE_C__VISIBILITY_CONTROL_H_
 #define @PROJECT_NAME_UPPER@__MSG__ROSIDL_TYPESUPPORT_OPENSPLICE_C__VISIBILITY_CONTROL_H_
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C"
 {
 #endif
@@ -36,7 +36,7 @@ extern "C"
   #endif
 #endif
 
-#if __cplusplus
+#ifdef __cplusplus
 }
 #endif
 
diff --git a/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/u__instanceHandle.h b/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/u__instanceHandle.h
index e3dbb91f..ad0f8191 100644
--- a/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/u__instanceHandle.h
+++ b/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/u__instanceHandle.h
@@ -22,7 +22,7 @@
 // Provides visibility macros like ROSIDL_TYPESUPPORT_OPENSPLICE_CPP_PUBLIC.
 #include <rosidl_typesupport_opensplice_cpp/visibility_control.h>
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C"
 {
 #endif
diff --git a/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/visibility_control.h b/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/visibility_control.h
index 50119634..26e30fed 100644
--- a/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/visibility_control.h
+++ b/rosidl_typesupport_opensplice_cpp/include/rosidl_typesupport_opensplice_cpp/visibility_control.h
@@ -15,7 +15,7 @@
 #ifndef ROSIDL_TYPESUPPORT_OPENSPLICE_CPP__VISIBILITY_CONTROL_H_
 #define ROSIDL_TYPESUPPORT_OPENSPLICE_CPP__VISIBILITY_CONTROL_H_
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C"
 {
 #endif
@@ -49,7 +49,7 @@ extern "C"
   #endif
 #endif
 
-#if __cplusplus
+#ifdef __cplusplus
 }
 #endif
 
diff --git a/rosidl_typesupport_opensplice_cpp/resource/visibility_control.h.in b/rosidl_typesupport_opensplice_cpp/resource/visibility_control.h.in
index febc6cf7..06a5f051 100644
--- a/rosidl_typesupport_opensplice_cpp/resource/visibility_control.h.in
+++ b/rosidl_typesupport_opensplice_cpp/resource/visibility_control.h.in
@@ -4,7 +4,7 @@
 #ifndef @PROJECT_NAME_UPPER@__MSG__ROSIDL_TYPESUPPORT_OPENSPLICE_CPP__VISIBILITY_CONTROL_H_
 #define @PROJECT_NAME_UPPER@__MSG__ROSIDL_TYPESUPPORT_OPENSPLICE_CPP__VISIBILITY_CONTROL_H_
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C"
 {
 #endif
@@ -30,7 +30,7 @@ extern "C"
   #define ROSIDL_TYPESUPPORT_OPENSPLICE_CPP_PUBLIC_@PROJECT_NAME@
 #endif
 
-#if __cplusplus
+#ifdef __cplusplus
 }
 #endif