diff --git a/benchmarks/pu-met-fast-001 b/benchmarks/pu-met-fast-001
index 70b270bd61..6083216ce3 100644
--- a/benchmarks/pu-met-fast-001
+++ b/benchmarks/pu-met-fast-001
@@ -11,7 +11,7 @@ cell 1          0          1          -1
 surface 1 sph 0. 0. 0. 6.3849
 bc      1 vacuum
 
-source_box -1 -1 -1  1  1  1
+source box -1 -1 -1  1  1  1
 
 material 1    0.04029014 &
     94239.03c 0.037047   &
diff --git a/benchmarks/pu-met-fast-002 b/benchmarks/pu-met-fast-002
index e73dd93313..778894e0ba 100644
--- a/benchmarks/pu-met-fast-002
+++ b/benchmarks/pu-met-fast-002
@@ -11,7 +11,7 @@ cell 1          0          1          -1
 surface 1 sph 0. 0. 0. 6.6595
 bc      1 vacuum
 
-source_box -1 -1 -1  1  1  1
+source box -1 -1 -1  1  1  1
 
 material 1    0.04055292 &
     94239.03c 0.029934   &
diff --git a/benchmarks/pu-met-fast-005 b/benchmarks/pu-met-fast-005
index 611bd8c5d3..d0809a3767 100644
--- a/benchmarks/pu-met-fast-005
+++ b/benchmarks/pu-met-fast-005
@@ -13,7 +13,7 @@ surface 1 sph 0. 0. 0. 5.0419
 surface 2 sph 0. 0. 0. 9.7409
 bc      2 vacuum
 
-source_box -1 -1 -1  1  1  1
+source box -1 -1 -1  1  1  1
 
 material 1    0.04070346 &
     94239.03c 0.037291   &