diff --git a/repos/base/Tupfile b/repos/base/Tupfile
index 3ba7a63fa..9a1b9196a 100644
--- a/repos/base/Tupfile
+++ b/repos/base/Tupfile
@@ -18,17 +18,5 @@ SED_FLAGS += -e "s|@ld@|$(LD)|"
 SED_FLAGS += -e "s|@ar@|$(AR)|"
 SED_FLAGS += -e "s|@ranlib@|$(RANLIB)|"
 
-ifeq (@(TUP_ARCH),i386)
-SED_FLAGS += -e 's|@spec_includes@|-I${includedir}/spec/x86_32 -I${includedir}/spec/x86 -I${includedir}/spec/32bit|'
-endif
-
-ifeq (@(TUP_ARCH),x86_64)
-SED_FLAGS += -e 's|@spec_includes@|-I${includedir}/spec/x86_64 -I${includedir}/spec/x86 -I${includedir}/spec/64bit|'
-endif
-
-ifeq (@(TUP_ARCH),arm64)
-SED_FLAGS += -e 's|@spec_includes@| -I${includedir}/spec/arm_64 -I${includedir}/spec/64bit|'
-endif
-
 : foreach *.pc.in |> !sed_pkgconfig_file |>
 : |> ln -s genode-base.pc %o |> $(PKG_CONFIG_DIR)/base.pc $(GENODE_DIR)/<pkg-config>
diff --git a/repos/base/genode-base.pc.in b/repos/base/genode-base.pc.in
index 90581ccf1..8f7e887bb 100644
--- a/repos/base/genode-base.pc.in
+++ b/repos/base/genode-base.pc.in
@@ -9,4 +9,4 @@ Name: base
 Description: Genode base repository
 URL: https://genode.org/
 Version: @VERSION@
-Cflags: -I${includedir} @spec_includes@ -I@toolchainincludedir@
+Cflags: -I${includedir} -I@toolchainincludedir@
diff --git a/repos/os/genode-os.pc.in b/repos/os/genode-os.pc.in
index 4754d3981..c95df9310 100644
--- a/repos/os/genode-os.pc.in
+++ b/repos/os/genode-os.pc.in
@@ -5,4 +5,4 @@ Description: Genode os repository
 URL: https://genode.org/
 Version: @VERSION@
 Requires: genode-base
-Cflags: @spec_includes@ -I${includedir}
+Cflags: -I${includedir}