diff --git a/lisp/Config.FreeBSD_gencgc b/lisp/Config.FreeBSD_gencgc
index c46fead832c8bf946c040dfa20b10d45a64fd2e8..06862f930330c45beb4d0bb292e622d2c5967a40 100644
--- a/lisp/Config.FreeBSD_gencgc
+++ b/lisp/Config.FreeBSD_gencgc
@@ -12,7 +12,7 @@ NM = nm -gp
 UNDEFSYMPATTERN = -Xlinker -u -Xlinker &
 ASSEM_SRC = x86-assem.S
 ARCH_SRC = x86-arch.c
-OS_SRC = FreeBSD-os.c os-common.c elf.c
+OS_SRC = FreeBSD-os.c os-common.c elf.c e_rem_pio2.c k_rem_pio2.c
 OS_LINK_FLAGS = -dynamic -export-dynamic
 OS_LIBS =
 GC_SRC = gencgc.c
diff --git a/lisp/Config.NetBSD_gencgc b/lisp/Config.NetBSD_gencgc
index f034dbf93959cf8a073ec4ad63c99a02587e0f9c..8836dbe05bbaf8bead537b48a53a436b376b40a8 100644
--- a/lisp/Config.NetBSD_gencgc
+++ b/lisp/Config.NetBSD_gencgc
@@ -41,6 +41,6 @@ ifeq ($(ARCH), powerpc)
   CFLAGS += -Dppc
 endif
 
-OS_SRC = NetBSD-os.c os-common.c elf.c
+OS_SRC = NetBSD-os.c os-common.c elf.c e_rem_pio2.c k_rem_pio2.c
 OS_LINK_FLAGS = -dynamic -export-dynamic
 OS_LIBS =