diff --git a/tutorials/combustion/dieselFoam/aachenBomb/constant/chemistryProperties b/tutorials/combustion/dieselFoam/aachenBomb/constant/chemistryProperties
index 0b78ecc8e..25e056dd4 100644
--- a/tutorials/combustion/dieselFoam/aachenBomb/constant/chemistryProperties
+++ b/tutorials/combustion/dieselFoam/aachenBomb/constant/chemistryProperties
@@ -8,7 +8,7 @@
 FoamFile
 {
     version     2.0;
-    format      binary;
+    format      ascii;
     class       dictionary;
     location    "constant";
     object      chemistryProperties;
diff --git a/tutorials/combustion/dieselFoam/aachenBomb/constant/thermophysicalProperties b/tutorials/combustion/dieselFoam/aachenBomb/constant/thermophysicalProperties
index aaa430bd6..30fbbfc8b 100644
--- a/tutorials/combustion/dieselFoam/aachenBomb/constant/thermophysicalProperties
+++ b/tutorials/combustion/dieselFoam/aachenBomb/constant/thermophysicalProperties
@@ -8,7 +8,7 @@
 FoamFile
 {
     version     2.0;
-    format      binary;
+    format      ascii;
     class       dictionary;
     location    "constant";
     object      thermophysicalProperties;