diff --git a/libsel4/sel4_arch_include/aarch32/sel4/sel4_arch/mapping.h b/libsel4/sel4_arch_include/aarch32/sel4/sel4_arch/mapping.h
index 5d1eea3f8..8c5f8b73d 100644
--- a/libsel4/sel4_arch_include/aarch32/sel4/sel4_arch/mapping.h
+++ b/libsel4/sel4_arch_include/aarch32/sel4/sel4_arch/mapping.h
@@ -23,7 +23,7 @@
 #define SEL4_MAPPING_LOOKUP_NO_PT 20
 #endif
 
-LIBSEL4_INLINE_FUNC seL4_Word seL4_MappingFailedLookupLevel()
+LIBSEL4_INLINE_FUNC seL4_Word seL4_MappingFailedLookupLevel(void)
 {
     return seL4_GetMR(SEL4_MAPPING_LOOKUP_LEVEL);
 }
diff --git a/libsel4/sel4_arch_include/ia32/sel4/sel4_arch/mapping.h b/libsel4/sel4_arch_include/ia32/sel4/sel4_arch/mapping.h
index 81defaaa2..9c77dd0d8 100644
--- a/libsel4/sel4_arch_include/ia32/sel4/sel4_arch/mapping.h
+++ b/libsel4/sel4_arch_include/ia32/sel4/sel4_arch/mapping.h
@@ -21,7 +21,7 @@
 #define SEL4_MAPPING_LOOKUP_NO_PT 22
 #endif
 
-LIBSEL4_INLINE_FUNC seL4_Word seL4_MappingFailedLookupLevel()
+LIBSEL4_INLINE_FUNC seL4_Word seL4_MappingFailedLookupLevel(void)
 {
     return seL4_GetMR(SEL4_MAPPING_LOOKUP_LEVEL);
 }
diff --git a/libsel4/sel4_arch_include/x86_64/sel4/sel4_arch/mapping.h b/libsel4/sel4_arch_include/x86_64/sel4/sel4_arch/mapping.h
index b84206b8a..d84aec863 100644
--- a/libsel4/sel4_arch_include/x86_64/sel4/sel4_arch/mapping.h
+++ b/libsel4/sel4_arch_include/x86_64/sel4/sel4_arch/mapping.h
@@ -18,7 +18,7 @@
 #define SEL4_MAPPING_LOOKUP_NO_PD 30
 #define SEL4_MAPPING_LOOKUP_NO_PDPT 39
 
-LIBSEL4_INLINE_FUNC seL4_Word seL4_MappingFailedLookupLevel()
+LIBSEL4_INLINE_FUNC seL4_Word seL4_MappingFailedLookupLevel(void)
 {
     return seL4_GetMR(SEL4_MAPPING_LOOKUP_LEVEL);
 }