diff --git a/library/LuaApi.cpp b/library/LuaApi.cpp
index 0bf19e93e..852f4e29d 100644
--- a/library/LuaApi.cpp
+++ b/library/LuaApi.cpp
@@ -1504,8 +1504,18 @@ static const luaL_Reg dfhack_gui_funcs[] = {
 
 /***** Job module *****/
 
-static bool jobEqual(df::job *job1, df::job *job2) { return *job1 == *job2; }
-static bool jobItemEqual(df::job_item *job1, df::job_item *job2) { return *job1 == *job2; }
+static bool jobEqual(const df::job *job1, const df::job *job2)
+{
+    CHECK_NULL_POINTER(job1);
+    CHECK_NULL_POINTER(job2);
+    return *job1 == *job2;
+}
+static bool jobItemEqual(const df::job_item *job1, const df::job_item *job2)
+{
+    CHECK_NULL_POINTER(job1);
+    CHECK_NULL_POINTER(job2);
+    return *job1 == *job2;
+}
 
 static const LuaWrapper::FunctionReg dfhack_job_module[] = {
     WRAPM(Job,cloneJobStruct),
diff --git a/library/modules/Job.cpp b/library/modules/Job.cpp
index 132dcfc4b..eccb70b7e 100644
--- a/library/modules/Job.cpp
+++ b/library/modules/Job.cpp
@@ -129,9 +129,6 @@ void DFHack::Job::deleteJobStruct(df::job *job, bool keptEverything)
 
 bool DFHack::operator== (const df::job_item &a, const df::job_item &b)
 {
-    CHECK_NULL_POINTER(&a);
-    CHECK_NULL_POINTER(&b);
-
     if (!(CMP(item_type) && CMP(item_subtype) &&
           CMP(mat_type) && CMP(mat_index) &&
           CMP(flags1.whole) && CMP(quantity) && CMP(vector_id) &&
@@ -152,9 +149,6 @@ bool DFHack::operator== (const df::job_item &a, const df::job_item &b)
 
 bool DFHack::operator== (const df::job &a, const df::job &b)
 {
-    CHECK_NULL_POINTER(&a);
-    CHECK_NULL_POINTER(&b);
-
     if (!(CMP(job_type) && CMP(job_subtype) &&
           CMP(mat_type) && CMP(mat_index) &&
           CMP(item_subtype) && CMP(item_category.whole) &&