diff --git a/Modules/Compiler/HP-ASM.cmake b/Modules/Compiler/HP-ASM.cmake
index 3eeab3f22..8aa7bdb7d 100644
--- a/Modules/Compiler/HP-ASM.cmake
+++ b/Modules/Compiler/HP-ASM.cmake
@@ -1 +1,3 @@
 SET(CMAKE_ASM_VERBOSE_FLAG "-v")
+
+set(CMAKE_ASM_SOURCE_FILE_EXTENSIONS s )