diff --git a/config/spl-build.m4 b/config/spl-build.m4
index 9fd97c06f..09e4b55eb 100644
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -244,12 +244,10 @@ AC_DEFUN([SPL_AC_DEBUG], [
 
 	AS_IF([test "x$enable_debug" = xyes],
 	[
-		AC_DEFINE([DEBUG], [1], [Define to 1 to enable debug])
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG -Werror"
 		DEBUG_CFLAGS="-DDEBUG -Werror"
 	],
 	[
-		AC_DEFINE([NDEBUG], [1], [Define to 1 to enable debug])
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DNDEBUG"
 		DEBUG_CFLAGS="-DNDEBUG"
 	])
diff --git a/configure b/configure
index a0d4cf890..979c38800 100755
--- a/configure
+++ b/configure
@@ -11630,21 +11630,11 @@ fi
 
 	if test "x$enable_debug" = xyes; then
 
-
-cat >>confdefs.h <<\_ACEOF
-#define DEBUG 1
-_ACEOF
-
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG -Werror"
 		DEBUG_CFLAGS="-DDEBUG -Werror"
 
 else
 
-
-cat >>confdefs.h <<\_ACEOF
-#define NDEBUG 1
-_ACEOF
-
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DNDEBUG"
 		DEBUG_CFLAGS="-DNDEBUG"
 
@@ -15110,21 +15100,11 @@ fi
 
 	if test "x$enable_debug" = xyes; then
 
-
-cat >>confdefs.h <<\_ACEOF
-#define DEBUG 1
-_ACEOF
-
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG -Werror"
 		DEBUG_CFLAGS="-DDEBUG -Werror"
 
 else
 
-
-cat >>confdefs.h <<\_ACEOF
-#define NDEBUG 1
-_ACEOF
-
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DNDEBUG"
 		DEBUG_CFLAGS="-DNDEBUG"
 
diff --git a/spl_config.h.in b/spl_config.h.in
index 540b79392..a22ca7b8b 100644
--- a/spl_config.h.in
+++ b/spl_config.h.in
@@ -3,9 +3,6 @@
 /* Atomic types use spinlocks */
 #undef ATOMIC_SPINLOCK
 
-/* Define to 1 to enable debug */
-#undef DEBUG
-
 /* Define to 1 to enable basic kmem accounting */
 #undef DEBUG_KMEM
 
@@ -211,9 +208,6 @@
    */
 #undef LT_OBJDIR
 
-/* Define to 1 to enable debug */
-#undef NDEBUG
-
 /* get_zone_counts() is needed */
 #undef NEED_GET_ZONE_COUNTS