diff --git a/libgnucash/engine/CMakeLists.txt b/libgnucash/engine/CMakeLists.txt
index 14ff75425c..a4d7f50d39 100644
--- a/libgnucash/engine/CMakeLists.txt
+++ b/libgnucash/engine/CMakeLists.txt
@@ -142,7 +142,7 @@ set (engine_SOURCES
   Query.cpp
   SchedXaction.c
   SX-book.cpp
-  SX-ttinfo.c
+  SX-ttinfo.cpp
   Scrub.cpp
   Scrub2.cpp
   Scrub3.cpp
diff --git a/libgnucash/engine/SX-ttinfo.c b/libgnucash/engine/SX-ttinfo.cpp
similarity index 100%
rename from libgnucash/engine/SX-ttinfo.c
rename to libgnucash/engine/SX-ttinfo.cpp
diff --git a/po/POTFILES.in b/po/POTFILES.in
index c7c246f348..cd90222e4b 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -692,7 +692,7 @@ libgnucash/engine/ScrubBusiness.c
 libgnucash/engine/Scrub.cpp
 libgnucash/engine/Split.cpp
 libgnucash/engine/SX-book.cpp
-libgnucash/engine/SX-ttinfo.c
+libgnucash/engine/SX-ttinfo.cpp
 libgnucash/engine/Transaction.cpp
 libgnucash/engine/TransLog.cpp
 libgnucash/gnc-module/example/gncmod-example.c