diff --git a/configure.ac b/configure.ac
index ddc3bca1b..6057b5019 100644
--- a/configure.ac
+++ b/configure.ac
@@ -355,14 +355,6 @@ _MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++14)
 _MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++11)
 _MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++03)
 AC_SUBST(CFG_CXXFLAGS_STD_NEWEST)
-# And likewise oldest standard (same list above, backwards)
-# This is used for internal testing
-_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=c++03)
-_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=c++11)
-_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=c++14)
-#_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=c++17)
-#_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=c++20)
-AC_SUBST(CFG_CXXFLAGS_STD_OLDEST)
 
 # Flags for compiling Verilator internals including parser, and Verilated files
 # These turn on extra warnings and are only used with 'configure --enable-ccwarn'
diff --git a/include/verilated.mk.in b/include/verilated.mk.in
index 39e263fa3..150196d0f 100644
--- a/include/verilated.mk.in
+++ b/include/verilated.mk.in
@@ -23,8 +23,6 @@ CFG_WITH_LONGTESTS = @CFG_WITH_LONGTESTS@
 CFG_CXXFLAGS_PROFILE = @CFG_CXXFLAGS_PROFILE@
 # Select newest language
 CFG_CXXFLAGS_STD_NEWEST = @CFG_CXXFLAGS_STD_NEWEST@
-# Select oldest language (for Verilator internal testing only)
-CFG_CXXFLAGS_STD_OLDEST = @CFG_CXXFLAGS_STD_OLDEST@
 # Compiler flags to use to turn off unused and generated code warnings, such as -Wno-div-by-zero
 CFG_CXXFLAGS_NO_UNUSED = @CFG_CXXFLAGS_NO_UNUSED@
 # Compiler flags that turn on extra warnings
diff --git a/test_regress/Makefile_obj b/test_regress/Makefile_obj
index 6795aeed4..945d0cdcd 100644
--- a/test_regress/Makefile_obj
+++ b/test_regress/Makefile_obj
@@ -41,8 +41,6 @@ CPPFLAGS += $(CPPFLAGS_ADD)
 ifeq ($(CFG_WITH_LONGTESTS),yes)
   ifeq ($(DRIVER_STD),newest)
     CPPFLAGS += $(CFG_CXXFLAGS_STD_NEWEST)
-  else ifeq ($(DRIVER_STD),oldest)
-    CPPFLAGS += $(CFG_CXXFLAGS_STD_OLDEST)
   endif
 endif
 
diff --git a/test_regress/t/t_verilated_all_oldest.pl b/test_regress/t/t_verilated_all_oldest.pl
index db800f7b0..103e2e197 100755
--- a/test_regress/t/t_verilated_all_oldest.pl
+++ b/test_regress/t/t_verilated_all_oldest.pl
@@ -11,6 +11,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(dist => 1);
 
 # This test now does nothing, because using DRIVER_STD=oldest tends to blow up glibc.
+# Support for DRIVER_STD=oldest was removed from makefiles. This file remains for commentary.
 
 ok(1);
 1;