diff --git a/src/bank.cpp b/src/bank.cpp
index 9ee1f8c8d..6053937b5 100644
--- a/src/bank.cpp
+++ b/src/bank.cpp
@@ -72,7 +72,7 @@ void sort_fission_bank()
 
   // TODO: C++17 introduces the exclusive_scan() function which could be
   // used to replace everything above this point in this function.
-  
+
   // We need a scratch vector to make permutation of the fission bank into
   // sorted order easy. Under normal usage conditions, the fission bank is
   // over provisioned, so we can use that as scratch space.
@@ -106,6 +106,11 @@ void sort_fission_bank()
 
 extern "C" int openmc_source_bank(void** ptr, int64_t* n)
 {
+  if (!ptr || !n) {
+    set_errmsg("Received null pointer.");
+    return OPENMC_E_INVALID_ARGUMENT;
+  }
+
   if (simulation::source_bank.size() == 0) {
     set_errmsg("Source bank has not been allocated.");
     return OPENMC_E_ALLOCATE;
@@ -118,6 +123,11 @@ extern "C" int openmc_source_bank(void** ptr, int64_t* n)
 
 extern "C" int openmc_fission_bank(void** ptr, int64_t* n)
 {
+  if (!ptr || !n) {
+    set_errmsg("Received null pointer.");
+    return OPENMC_E_INVALID_ARGUMENT;
+  }
+
   if (simulation::fission_bank.size() == 0) {
     set_errmsg("Fission bank has not been allocated.");
     return OPENMC_E_ALLOCATE;