diff --git a/indra/llprimitive/CMakeLists.txt b/indra/llprimitive/CMakeLists.txt
index 97e1ebde47..96d2227f52 100644
--- a/indra/llprimitive/CMakeLists.txt
+++ b/indra/llprimitive/CMakeLists.txt
@@ -7,6 +7,7 @@ include(LLCommon)
 include(LLMath)
 include(LLMessage)
 include(LLXML)
+include(HACD)
 
 include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
@@ -15,6 +16,7 @@ include_directories(
     ${LLXML_INCLUDE_DIRS}
     ${LIBS_PREBUILT_DIR}/include/collada
     ${LIBS_PREBUILT_DIR}/include/collada/1.4
+    ${HACD_INCLUDE_DIR}
     )
 
 set(llprimitive_SOURCE_FILES