diff --git a/src/StepFile/stepread.c b/src/StepFile/stepread.c
index aeff1e9181..e0fd83b027 100644
--- a/src/StepFile/stepread.c
+++ b/src/StepFile/stepread.c
@@ -85,7 +85,7 @@ FILE* stepread_setinput (char* nomfic)
 {
   FILE* newin ;
   if (strlen(nomfic) == 0) return stepin ;
-  newin = OSD_OpenFile(nomfic,"r");
+  newin = OSD_OpenFile(nomfic,"rb");
 
   if (newin == NULL) {
     return NULL ;
diff --git a/tests/bugs/step/bug30397 b/tests/bugs/step/bug30397
new file mode 100644
index 0000000000..ad1244c233
--- /dev/null
+++ b/tests/bugs/step/bug30397
@@ -0,0 +1,11 @@
+puts "========================"
+puts "0030397: Data Exchange - STEP Reader extension to support entities which have a text description field with not supported symbols"
+puts "========================"
+
+ReadStep D [locate_data_file bug31397.stp]
+
+set state [data c]
+
+if { [regexp "141153" $state] != 1 } {
+   puts "Error : wrong count of transferred roots"
+}
\ No newline at end of file