diff --git a/trajopt/CMakeLists.txt b/trajopt/CMakeLists.txt
index f9699807..0d441a34 100644
--- a/trajopt/CMakeLists.txt
+++ b/trajopt/CMakeLists.txt
@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.10.0)
 # Extract package name and version
 find_package(ros_industrial_cmake_boilerplate REQUIRED)
 extract_package_metadata(pkg)
-project(${pkg_extracted_name} VERSION ${pkg_extracted_version} LANGUAGES CXX)
+project(${pkg_extracted_name} VERSION ${pkg_extracted_version} LANGUAGES C CXX)
 
 if(WIN32)
   set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
diff --git a/trajopt_ifopt/CMakeLists.txt b/trajopt_ifopt/CMakeLists.txt
index ce04396d..59a6d2ce 100644
--- a/trajopt_ifopt/CMakeLists.txt
+++ b/trajopt_ifopt/CMakeLists.txt
@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.10.0)
 # Extract package name and version
 find_package(ros_industrial_cmake_boilerplate REQUIRED)
 extract_package_metadata(pkg)
-project(${pkg_extracted_name} VERSION ${pkg_extracted_version} LANGUAGES CXX)
+project(${pkg_extracted_name} VERSION ${pkg_extracted_version} LANGUAGES C CXX)
 
 if(WIN32)
   set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
diff --git a/trajopt_optimizers/trajopt_sqp/CMakeLists.txt b/trajopt_optimizers/trajopt_sqp/CMakeLists.txt
index 3bd7f051..51a282f0 100644
--- a/trajopt_optimizers/trajopt_sqp/CMakeLists.txt
+++ b/trajopt_optimizers/trajopt_sqp/CMakeLists.txt
@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.10.0)
 # Extract package name and version
 find_package(ros_industrial_cmake_boilerplate REQUIRED)
 extract_package_metadata(pkg)
-project(${pkg_extracted_name} VERSION ${pkg_extracted_version} LANGUAGES CXX)
+project(${pkg_extracted_name} VERSION ${pkg_extracted_version} LANGUAGES C CXX)
 
 if(WIN32)
   set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)