diff --git a/libsel4/arch_include/arm/interfaces/sel4arch.xml b/libsel4/arch_include/arm/interfaces/sel4arch.xml
index 92fdbd333..47e74feb1 100644
--- a/libsel4/arch_include/arm/interfaces/sel4arch.xml
+++ b/libsel4/arch_include/arm/interfaces/sel4arch.xml
@@ -19,11 +19,11 @@
 		</method>
 	</interface>
     <interface name="seL4_ARM_IOPageTable">
-        <method id="ARMIOPageTableMap" name="Map" config="CONFIG_ARM_SMMU">
+        <method id="ARMIOPageTableMap" name="Map" condition="defined(CONFIG_ARM_SMMU)">
             <param dir="in" name="iospace" type="seL4_ARM_IOSpace"/>
             <param dir="in" name="ioaddr" type="seL4_Word"/>
         </method>
-        <method id="ARMIOPageTableUnmap" name="Unmap" config="CONFIG_ARM_SMMU">
+        <method id="ARMIOPageTableUnmap" name="Unmap" condition="defined(CONFIG_ARM_SMMU)">
         </method>
     </interface>
 	<interface name="seL4_ARM_Page">
@@ -39,7 +39,7 @@
 			<param dir="in" name="attr" type="seL4_ARM_VMAttributes"/>
 		</method>
 		<method id="ARMPageUnmap" name="Unmap"/>
-        <method id="ARMPageMapIO" name="MapIO" config="CONFIG_ARM_SMMU">
+        <method id="ARMPageMapIO" name="MapIO" condition="defined(CONFIG_ARM_SMMU)">
             <param dir="in" name="iospace" type="seL4_ARM_IOSpace"/>
             <param dir="in" name="rights" type="seL4_CapRights"/>
             <param dir="in" name="ioaddr" type="seL4_Word"/>
diff --git a/libsel4/include/interfaces/sel4.xml b/libsel4/include/interfaces/sel4.xml
index bdb09478f..56b29a392 100644
--- a/libsel4/include/interfaces/sel4.xml
+++ b/libsel4/include/interfaces/sel4.xml
@@ -75,14 +75,14 @@
 		</method>
 		<method id="TCBUnbindNotification" name="UnbindNotification">
 		</method>
-                <method id="TCBSetBreakpoint" name="SetBreakpoint" config="CONFIG_HARDWARE_DEBUG_API">
+                <method id="TCBSetBreakpoint" name="SetBreakpoint" condition="defined(CONFIG_HARDWARE_DEBUG_API)">
                     <param dir="in" name="bp_num" type="seL4_Uint16"/>
                     <param dir="in" name="vaddr" type="seL4_Word"/>
                     <param dir="in" name="type" type="seL4_Word"/>
                     <param dir="in" name="size" type="seL4_Word"/>
                     <param dir="in" name="rw" type="seL4_Word"/>
                 </method>
-                <method id="TCBGetBreakpoint" name="GetBreakpoint" config="CONFIG_HARDWARE_DEBUG_API">
+                <method id="TCBGetBreakpoint" name="GetBreakpoint" condition="defined(CONFIG_HARDWARE_DEBUG_API)">
                     <param dir="in" name="bp_num" type="seL4_Uint16"/>
                     <param dir="out" name="vaddr" type="seL4_Word"/>
                     <param dir="out" name="type" type="seL4_Word"/>
@@ -90,10 +90,10 @@
                     <param dir="out" name="rw" type="seL4_Word"/>
                     <param dir="out" name="is_enabled" type="seL4_Bool"/>
                 </method>
-                <method id="TCBUnsetBreakpoint" name="UnsetBreakpoint" config="CONFIG_HARDWARE_DEBUG_API">
+                <method id="TCBUnsetBreakpoint" name="UnsetBreakpoint" condition="defined(CONFIG_HARDWARE_DEBUG_API)">
                     <param dir="in" name="bp_num" type="seL4_Uint16"/>
                 </method>
-                <method id="TCBConfigureSingleStepping" name="ConfigureSingleStepping" config="CONFIG_HARDWARE_DEBUG_API">
+                <method id="TCBConfigureSingleStepping" name="ConfigureSingleStepping" condition="defined(CONFIG_HARDWARE_DEBUG_API)">
                     <param dir="in" name="bp_num" type="seL4_Uint16"/>
                     <param dir="in" name="num_instructions" type="seL4_Word"/>
                     <param dir="out" name="bp_was_consumed" type="seL4_Bool"/>
diff --git a/libsel4/sel4_arch_include/aarch32/interfaces/sel4arch.xml b/libsel4/sel4_arch_include/aarch32/interfaces/sel4arch.xml
index e28150d21..4cf6b29a6 100644
--- a/libsel4/sel4_arch_include/aarch32/interfaces/sel4arch.xml
+++ b/libsel4/sel4_arch_include/aarch32/interfaces/sel4arch.xml
@@ -47,20 +47,20 @@
 		</method>
     </interface>
     <interface name="seL4_ARM_VCPU">
-        <method id="ARMVCPUSetTCB" name="SetTCB" config="CONFIG_ARM_HYPERVISOR_SUPPORT">
+        <method id="ARMVCPUSetTCB" name="SetTCB" condition="defined(CONFIG_ARM_HYPERVISOR_SUPPORT)">
             <param dir="in" name="tcb" type="seL4_TCB" />
         </method>
-        <method id="ARMVCPUInjectIRQ" name="InjectIRQ" config="CONFIG_ARM_HYPERVISOR_SUPPORT">
+        <method id="ARMVCPUInjectIRQ" name="InjectIRQ" condition="defined(CONFIG_ARM_HYPERVISOR_SUPPORT)">
             <param dir="in" name="virq" type="seL4_Uint16"/>
             <param dir="in" name="priority" type="seL4_Uint8"/>
             <param dir="in" name="group" type="seL4_Uint8"/>
             <param dir="in" name="index" type="seL4_Uint8"/>
         </method>
-        <method id="ARMVCPUReadReg" name="ReadRegs" config="CONFIG_ARM_HYPERVISOR_SUPPORT">
+        <method id="ARMVCPUReadReg" name="ReadRegs" condition="defined(CONFIG_ARM_HYPERVISOR_SUPPORT)">
             <param dir="in" name="field" type="seL4_Uint32"/>
             <param dir="out" name="value" type="seL4_Uint32"/>
         </method>
-        <method id="ARMVCPUWriteReg" name="WriteRegs" config="CONFIG_ARM_HYPERVISOR_SUPPORT">
+        <method id="ARMVCPUWriteReg" name="WriteRegs" condition="defined(CONFIG_ARM_HYPERVISOR_SUPPORT)">
             <param dir="in" name="field" type="seL4_Uint32"/>
             <param dir="in" name="value" type="seL4_Uint32"/>
         </method>
diff --git a/libsel4/tools/syscall_stub_gen.py b/libsel4/tools/syscall_stub_gen.py
index e2394f74e..ae044bd96 100644
--- a/libsel4/tools/syscall_stub_gen.py
+++ b/libsel4/tools/syscall_stub_gen.py
@@ -683,7 +683,7 @@ def parse_xml_file(input_file, valid_types):
         for method in interface.getElementsByTagName("method"):
             method_name = method.getAttribute("name")
             method_id = method.getAttribute("id")
-            method_config = method.getAttribute("config")
+            method_condition = method.getAttribute("condition")
 
             #
             # Get parameters.
@@ -703,7 +703,7 @@ def parse_xml_file(input_file, valid_types):
                     input_params.append(Parameter(param_name, param_type))
                 else:
                     output_params.append(Parameter(param_name, param_type))
-            methods.append((interface_name, method_name, method_id, input_params, output_params, method_config))
+            methods.append((interface_name, method_name, method_id, input_params, output_params, method_condition))
 
     return (methods, structs)
 
@@ -781,12 +781,12 @@ def generate_stub_file(arch, wordsize, input_files, output_file, use_only_ipc_bu
     result.append("/*")
     result.append(" * Generated stubs.")
     result.append(" */")
-    for (interface_name, method_name, method_id, inputs, outputs, config) in methods:
-        if config != "":
-            result.append("#ifdef %s" % config)
+    for (interface_name, method_name, method_id, inputs, outputs, condition) in methods:
+        if condition != "":
+            result.append("#if %s" % condition)
         result.append(generate_stub(arch, wordsize, interface_name, method_name,
                                     method_id, inputs, outputs, structs, use_only_ipc_buffer))
-        if config != "":
+        if condition != "":
             result.append("#endif")
 
     # Print footer.
diff --git a/tools/invocation_header_gen.py b/tools/invocation_header_gen.py
index f489a08bb..83e3fc35a 100755
--- a/tools/invocation_header_gen.py
+++ b/tools/invocation_header_gen.py
@@ -150,7 +150,7 @@ def parse_xml(xml_file):
 
     invocation_labels = []
     for method in doc.getElementsByTagName("method"):
-        invocation_labels.append((str(method.getAttribute("id")), str(method.getAttribute("config"))))
+        invocation_labels.append((str(method.getAttribute("id")), str(method.getAttribute("condition"))))
 
     return invocation_labels