diff --git a/c/CMakeLists.txt b/c/CMakeLists.txt
index 65c588e46..e4440981a 100644
--- a/c/CMakeLists.txt
+++ b/c/CMakeLists.txt
@@ -502,7 +502,7 @@ set(qpid-proton-noncore-src
 add_library (qpid-proton SHARED
   $<TARGET_OBJECTS:qpid-proton-core-objects>
   $<TARGET_OBJECTS:qpid-proton-platform-io-objects>
-  $<TARGET_OBJECTS:qpid-proton-proactor-objects>
+  $<$<TARGET_EXISTS:qpid-proton-proactor-objects>:$<TARGET_OBJECTS:qpid-proton-proactor-objects>>
   ${qpid-proton-noncore-src})
 target_link_libraries (qpid-proton LINK_PRIVATE ${SSL_LIB} ${SASL_LIB} ${TIME_LIB} ${PLATFORM_LIBS} ${PROACTOR_LIBS})
 set_target_properties (qpid-proton
diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
index b7d61c556..712e26468 100644
--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -17,6 +17,11 @@
 # under the License.
 #
 
+# Proton cpp requires the proactor library so don't build if that's not present
+if (NOT TARGET qpid-proton-proactor)
+  return()
+endif()
+
 include(CMakeDependentOption)
 enable_language(CXX)