diff --git a/lang/cem/libcc.ansi/stdio/fopen.c b/lang/cem/libcc.ansi/stdio/fopen.c
index bc2e1ed6b..af11acd57 100644
--- a/lang/cem/libcc.ansi/stdio/fopen.c
+++ b/lang/cem/libcc.ansi/stdio/fopen.c
@@ -73,14 +73,16 @@ fopen(const char *name, const char *mode)
 	while (*mode) {
 		switch(*mode++) {
 		case 'b':
-			break;
+			continue;
 		case '+':
 			rwmode = O_RDWR;
 			flags |= _IOREAD | _IOWRITE;
-			break;
+			continue;
+		/* The sequence may be followed by additional characters */
 		default:
-			return (FILE *)NULL;
+			break;
 		}
+		break;
 	}
 
 	/* Perform a creat() when the file should be truncated or when
diff --git a/lang/cem/libcc.ansi/stdio/freopen.c b/lang/cem/libcc.ansi/stdio/freopen.c
index 41887f861..32965362c 100644
--- a/lang/cem/libcc.ansi/stdio/freopen.c
+++ b/lang/cem/libcc.ansi/stdio/freopen.c
@@ -56,14 +56,16 @@ freopen(const char *name, const char *mode, FILE *stream)
 	while (*mode) {
 		switch(*mode++) {
 		case 'b':
-			break;
+			continue;
 		case '+':
 			rwmode = O_RDWR;
 			flags |= _IOREAD | _IOWRITE;
-			break;
+			continue;
+		/* The sequence may be followed by aditional characters */
 		default:
-			return (FILE *)NULL;
+			break;
 		}
+		break;
 	}
 
 	if ((rwflags & O_TRUNC)