diff --git a/src/file.c b/src/file.c
index 2f7279bfc..548456dd7 100644
--- a/src/file.c
+++ b/src/file.c
@@ -164,7 +164,7 @@ static unsigned char *
 do_transform_source (FileOpContext *ctx, unsigned char *source)
 {
     size_t j, k, l, len;
-    unsigned char *fnsource = x_basename (source);
+    unsigned const char *fnsource = x_basename (source);
     int next_reg;
     enum CaseConvs case_conv = NO_CONV;
     static unsigned char fntarget[MC_MAXPATHLEN];
diff --git a/src/main.c b/src/main.c
index e00e1a455..c629c91ac 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2013,7 +2013,7 @@ handle_args (int argc, char *argv[])
 {
     char *tmp;
     poptContext ctx;
-    char *base;
+    const char *base;
     int c;
 
     ctx =