diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,29 +12,47 @@
   SET(LEMON_VERSION $ENV{LEMON_VERSION} CACHE STRING "LEMON version string.")
 ELSE()
   EXECUTE_PROCESS(
-    COMMAND ${PYTHON_EXECUTABLE} ./scripts/chg-len.py
+    COMMAND
+    hg log -r. --template "{latesttag}"
     WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-    OUTPUT_VARIABLE HG_REVISION_PATH
+    OUTPUT_VARIABLE HG_REVISION_TAG
     ERROR_QUIET
     OUTPUT_STRIP_TRAILING_WHITESPACE
   )
   EXECUTE_PROCESS(
-    COMMAND hg id -i
+    COMMAND
+    hg log -r. --template "{latesttagdistance}"
     WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-    OUTPUT_VARIABLE HG_REVISION
+    OUTPUT_VARIABLE HG_REVISION_DIST
     ERROR_QUIET
     OUTPUT_STRIP_TRAILING_WHITESPACE
   )
-  IF(HG_REVISION STREQUAL "")
+  EXECUTE_PROCESS(
+    COMMAND
+    hg log -r. --template "{node|short}"
+    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+    OUTPUT_VARIABLE HG_REVISION_ID
+    ERROR_QUIET
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+
+  IF(HG_REVISION_TAG STREQUAL "")
     SET(HG_REVISION_ID "hg-tip")
   ELSE()
-    IF(HG_REVISION_PATH STREQUAL "")
-      SET(HG_REVISION_ID ${HG_REVISION})
+    IF(HG_REVISION_TAG STREQUAL "null")
+      SET(HG_REVISION_TAG "trunk")
+    ELSEIF(HG_REVISION_TAG MATCHES "^r")
+      STRING(SUBSTRING ${HG_REVISION_TAG} 1 -1 HG_REVISION_TAG)
+    ENDIF()
+    IF(HG_REVISION_DIST STREQUAL "0")
+      SET(HG_REVISION ${HG_REVISION_TAG})
     ELSE()
-      SET(HG_REVISION_ID ${HG_REVISION_PATH}.${HG_REVISION})
+      SET(HG_REVISION
+	"${HG_REVISION_TAG}+${HG_REVISION_DIST}-${HG_REVISION_ID}")
     ENDIF()
   ENDIF()
-  SET(LEMON_VERSION ${HG_REVISION_ID} CACHE STRING "LEMON version string.")
+
+  SET(LEMON_VERSION ${HG_REVISION} CACHE STRING "LEMON version string.")
 ENDIF()
 
 SET(PROJECT_VERSION ${LEMON_VERSION})