diff --git a/Misc/NEWS b/Misc/NEWS
index a961f6a..7da118a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -179,6 +179,9 @@
 Build
 -----
 
+- Issue #15819: The Include directory in the build tree is already searched;
+  drop unused code trying to add it again.
+
 - Issue #27566: Fix clean target in freeze makefile (patch by Lisa Roach)
 
 - Issue #27983: Cause lack of llvm-profdata tool when using clang as
diff --git a/configure b/configure
index d9a22eb..6cbdf2a 100755
--- a/configure
+++ b/configure
@@ -687,7 +687,6 @@
 HGBRANCH
 HGTAG
 HGVERSION
-BASECPPFLAGS
 SVNVERSION
 ARFLAGS
 ac_ct_AR
@@ -5748,20 +5747,6 @@
 fi
 
 
-if test "$abs_srcdir" != "$abs_builddir"; then
-    # If we're building out-of-tree make sure Include (in the current dir)
-    # gets picked up before its $srcdir counterpart in order for Python-ast.h
-    # and graminit.h to get picked up from the correct directory.
-    # (A side effect of this is that these resources will automatically be
-    #  regenerated when building out-of-tree, regardless of whether or not
-    #  the $srcdir counterpart is up-to-date.  This is an acceptable trade
-    #  off.)
-    BASECPPFLAGS="-IInclude"
-else
-    BASECPPFLAGS=""
-fi
-
-
 
 
 # Extract the first word of "hg", so it can be a program name with args.
diff --git a/configure.ac b/configure.ac
index 5edbf7b..8b694f0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -988,20 +988,6 @@
 	SVNVERSION="echo Unversioned directory"
 fi
 
-AC_SUBST(BASECPPFLAGS)
-if test "$abs_srcdir" != "$abs_builddir"; then
-    # If we're building out-of-tree make sure Include (in the current dir)
-    # gets picked up before its $srcdir counterpart in order for Python-ast.h
-    # and graminit.h to get picked up from the correct directory.
-    # (A side effect of this is that these resources will automatically be
-    #  regenerated when building out-of-tree, regardless of whether or not
-    #  the $srcdir counterpart is up-to-date.  This is an acceptable trade
-    #  off.)
-    BASECPPFLAGS="-IInclude"
-else
-    BASECPPFLAGS=""
-fi
-
 AC_SUBST(HGVERSION)
 AC_SUBST(HGTAG)
 AC_SUBST(HGBRANCH)