diff --git a/changelog.md b/changelog.md
index 9622c0a400e14adbeaa2b594e34b59e0bf81e620..8538c62b0086a083ef5c5e60884637e20f2ff5df 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,7 +1,7 @@
 Changes in tpcclib
 ==================
 
-## version 0.6.18 (2018-01-29, in development)
+## version 0.6.18 (2018-01-31)
 
 - Updated documents.
 - Added applications tacdelna, tacnames, iftren, and addvers in v2.
@@ -16,6 +16,7 @@ Changes in tpcclib
 - Added function iftReplaceKey() in libtpcift in v2.
 - IMG quaterns filled with pixel sizes when reading ECAT 6.3 or 7 in libtpcimgio in v1.
 - pixdim[0] set to 1 (previously -1) in imgSetNiftiHeader() in libtpcimgio in v1.
+- Renamed v2/libtpctac/tacnames.c to v2/libtpctac/tacname.c
 - OpenMP included in all 64-bit builds in `CMakeLists.txt`
 - CMake minimum version changed from 2.8.12 to 3.5.1, although new features are not yet applied.
 
diff --git a/v2/libtpctac/CMakeLists.txt b/v2/libtpctac/CMakeLists.txt
index 6cd46dcc7c3e39e609aea0b6a403894086d30ad8..f963e0e5fcaf22ee069ec2ec12294ca98739d236 100644
--- a/v2/libtpctac/CMakeLists.txt
+++ b/v2/libtpctac/CMakeLists.txt
@@ -10,7 +10,7 @@ set(libtpctac_HEADER_FILES "${CMAKE_CURRENT_SOURCE_DIR}" PARENT_SCOPE)
 add_library (tpctac STATIC 
   tac.c tacio.c tacift.c simpleio.c dftio.c
   sifio.c tacnan.c tacselect.c tacorder.c 
-  taccomp.c tacunits.c tacnames.c
+  taccomp.c tacunits.c tacname.c
   pmodio.c taccsv.c hcio.c qviewio.c tacabss.c
   tacx.c tacy.c tacw.c tacdc.c
 )
@@ -46,7 +46,7 @@ install (
 add_executable (libtpctac libtpctac.c 
   test_tac.c test_tacio.c test_tacift.c test_simpleio.c test_dftio.c
   test_sifio.c test_tacnan.c test_tacselect.c test_tacorder.c 
-  test_taccomp.c test_tacunits.c test_tacnames.c 
+  test_taccomp.c test_tacunits.c test_tacname.c 
   test_pmodio.c test_taccsv.c test_hcio.c test_qviewio.c test_tacabss.c
   test_tacx.c test_tacy.c test_tacw.c test_tacdc.c
 ) 
diff --git a/v2/libtpctac/tacnames.c b/v2/libtpctac/tacname.c
similarity index 99%
rename from v2/libtpctac/tacnames.c
rename to v2/libtpctac/tacname.c
index b244d72f97322e6eaf227cabd24f303e13072a45..a186caac359bc39ea38a98aead54875957378488 100644
--- a/v2/libtpctac/tacnames.c
+++ b/v2/libtpctac/tacname.c
@@ -1,4 +1,4 @@
-/** @file tacnames.c
+/** @file tacname.c
  *  @brief Working with TAC names in TAC struct.
  */
 /*****************************************************************************/
diff --git a/v2/libtpctac/test_tacnames.c b/v2/libtpctac/test_tacname.c
similarity index 100%
rename from v2/libtpctac/test_tacnames.c
rename to v2/libtpctac/test_tacname.c
diff --git a/v2/libtpctac/test_tpctac.h b/v2/libtpctac/test_tpctac.h
index ed08dc4b8da280c3dd72245f609066b0a8efef4a..3ab40c9081bbf9c71b29d3a97efd1715fdca784d 100644
--- a/v2/libtpctac/test_tpctac.h
+++ b/v2/libtpctac/test_tpctac.h
@@ -126,7 +126,7 @@ int test_tacCompareWeights(TPCSTATUS *status);
 int test_tacXUnitConvert(TPCSTATUS *status);
 int test_tacYUnitConvert(TPCSTATUS *status);
 /*****************************************************************************/
-/* tacnames */
+/* tacname */
 int test_tacIndividualNames(TPCSTATUS *status);
 int test_tacEnsureNames(TPCSTATUS *status);
 /*****************************************************************************/
diff --git a/v2/libtpctac/tpctac.h b/v2/libtpctac/tpctac.h
index 05d1b514b83c9d42e351c2cf0ff34b830f8b50ba..199c4a80095000a7b785d54d92928f9c5f71a457 100644
--- a/v2/libtpctac/tpctac.h
+++ b/v2/libtpctac/tpctac.h
@@ -281,7 +281,7 @@ int tacYUnitConvert(TAC *d, const int u, TPCSTATUS *status);
 /*****************************************************************************/
 
 /*****************************************************************************/
-/* tacnames */
+/* tacname */
 int tacIndividualNames(TAC *tac);
 void tacEnsureNames(TAC *tac);
 /*****************************************************************************/