diff --git a/libsel4/arch_include/arm/interfaces/sel4arch.xml b/libsel4/arch_include/arm/interfaces/sel4arch.xml
index 1166ced61..90665d13f 100644
--- a/libsel4/arch_include/arm/interfaces/sel4arch.xml
+++ b/libsel4/arch_include/arm/interfaces/sel4arch.xml
@@ -254,6 +254,11 @@
             description="The offset, relative to the start of the page inclusive."/>
             <param dir="in" name="end_offset" type="seL4_Word"
             description="The offset, relative to the start of the page exclusive."/>
+            <error name="seL4_FailedLookup">
+                <description>
+                    The VSpace of <texttt text="_service"/> is not assigned to an ASID pool.
+                </description>
+            </error>
             <error name="seL4_IllegalOperation">
                 <description>
                     The <texttt text="_service"/> is a CPtr to a capability of the wrong type.
@@ -287,6 +292,11 @@
             description="The offset, relative to the start of the page inclusive."/>
             <param dir="in" name="end_offset" type="seL4_Word"
             description="The offset, relative to the start of the page exclusive."/>
+            <error name="seL4_FailedLookup">
+                <description>
+                    The VSpace of <texttt text="_service"/> is not assigned to an ASID pool.
+                </description>
+            </error>
             <error name="seL4_IllegalOperation">
                 <description>
                     The <texttt text="_service"/> is a CPtr to a capability of the wrong type.
@@ -319,6 +329,11 @@
             description="The offset, relative to the start of the page inclusive."/>
             <param dir="in" name="end_offset" type="seL4_Word"
             description="The offset, relative to the start of the page exclusive."/>
+            <error name="seL4_FailedLookup">
+                <description>
+                    The VSpace of <texttt text="_service"/> is not assigned to an ASID pool.
+                </description>
+            </error>
             <error name="seL4_IllegalOperation">
                 <description>
                     The <texttt text="_service"/> is a CPtr to a capability of the wrong type.
@@ -352,6 +367,11 @@
             description="The offset, relative to the start of the page inclusive."/>
             <param dir="in" name="end_offset" type="seL4_Word"
             description="The offset, relative to the start of the page exclusive."/>
+            <error name="seL4_FailedLookup">
+                <description>
+                    The VSpace of <texttt text="_service"/> is not assigned to an ASID pool.
+                </description>
+            </error>
             <error name="seL4_IllegalOperation">
                 <description>
                     The <texttt text="_service"/> is a CPtr to a capability of the wrong type.
@@ -470,6 +490,11 @@
                     There are no more ASIDs available in <texttt text="_service"/>.
                 </description>
             </error>
+            <error name="seL4_FailedLookup">
+                <description>
+                    The ASID pool of <texttt text="_service"/> is no longer assigned.
+                </description>
+            </error>
             <error name="seL4_IllegalOperation">
                 <description>
                     The <texttt text="_service"/> is a CPtr to a capability of the wrong type.
diff --git a/libsel4/arch_include/x86/interfaces/sel4arch.xml b/libsel4/arch_include/x86/interfaces/sel4arch.xml
index 3cbff4dd5..4045e2275 100644
--- a/libsel4/arch_include/x86/interfaces/sel4arch.xml
+++ b/libsel4/arch_include/x86/interfaces/sel4arch.xml
@@ -212,6 +212,11 @@
                     All required page tables are already mapped in <texttt text="iospace"/> at <texttt text="ioaddr"/>.
                 </description>
             </error>
+            <error name="seL4_FailedLookup">
+                <description>
+                    The <texttt text="iospace"/> does not have a paging structure at the required level mapped at <texttt text="ioaddr"/>.
+                </description>
+            </error>
             <error name="seL4_IllegalOperation">
                 <description>
                     The <texttt text="_service"/> is a CPtr to a capability of the wrong type.