diff --git a/Modules/CMakeCCompilerId.c.in b/Modules/CMakeCCompilerId.c.in
index 06aa9bf06..7771dbf25 100644
--- a/Modules/CMakeCCompilerId.c.in
+++ b/Modules/CMakeCCompilerId.c.in
@@ -67,6 +67,10 @@
 
 #elif defined(__DECC)
 # define COMPILER_ID "Compaq"
+  /* __DECC_VER = VVRRTPPPP */
+# define COMPILER_VERSION_MAJOR DEC(__DECC_VER/10000000)
+# define COMPILER_VERSION_MINOR DEC(__DECC_VER/100000  % 100)
+# define COMPILER_VERSION_PATCH DEC(__DECC_VER         % 10000)
 
 #elif defined(__IBMC__)
 # if defined(__COMPILER_VER__)
diff --git a/Modules/CMakeCXXCompilerId.cpp.in b/Modules/CMakeCXXCompilerId.cpp.in
index 95fc852d6..47cd45c32 100644
--- a/Modules/CMakeCXXCompilerId.cpp.in
+++ b/Modules/CMakeCXXCompilerId.cpp.in
@@ -69,6 +69,10 @@
 
 #elif defined(__DECCXX)
 # define COMPILER_ID "Compaq"
+  /* __DECCXX_VER = VVRRTPPPP */
+# define COMPILER_VERSION_MAJOR DEC(__DECCXX_VER/10000000)
+# define COMPILER_VERSION_MINOR DEC(__DECCXX_VER/100000  % 100)
+# define COMPILER_VERSION_PATCH DEC(__DECCXX_VER         % 10000)
 
 #elif defined(__IBMCPP__)
 # if defined(__COMPILER_VER__)