diff --git a/capchild/capture_sync.c b/capchild/capture_sync.c
index c3bd19cc5e..25879ebdfb 100644
--- a/capchild/capture_sync.c
+++ b/capchild/capture_sync.c
@@ -1711,7 +1711,7 @@ sync_pipe_input_cb(gint source, gpointer user_data)
             message = end + 1;
         }
 
-        capture_input_cfilter_error_message(cap_session, indx, (char*)message);
+        capture_input_cfilter_error_message(cap_session, indx, message);
         /* the capture child will close the sync_pipe, nothing to do for now */
         break;
         }
diff --git a/capchild/capture_sync.h b/capchild/capture_sync.h
index 41c566de1a..dafd787a4e 100644
--- a/capchild/capture_sync.h
+++ b/capchild/capture_sync.h
@@ -136,7 +136,7 @@ capture_input_error_message(capture_session *cap_session, char *error_msg,
  */
 extern void
 capture_input_cfilter_error_message(capture_session *cap_session, guint i,
-                                    char *error_message);
+                                    const char *error_message);
 
 /**
  * Capture child closed its side of the pipe, report any error and
diff --git a/tshark.c b/tshark.c
index 41025d336c..ae39a3d251 100644
--- a/tshark.c
+++ b/tshark.c
@@ -2536,7 +2536,7 @@ capture_input_error_message(capture_session *cap_session _U_, char *error_msg, c
 
 /* capture child detected an capture filter related error */
 void
-capture_input_cfilter_error_message(capture_session *cap_session, guint i, char *error_message)
+capture_input_cfilter_error_message(capture_session *cap_session, guint i, const char *error_message)
 {
   capture_options *capture_opts = cap_session->capture_opts;
   dfilter_t         *rfcode = NULL;
diff --git a/ui/capture.c b/ui/capture.c
index bf248fd4b2..8e99e93253 100644
--- a/ui/capture.c
+++ b/ui/capture.c
@@ -572,7 +572,7 @@ capture_input_error_message(capture_session *cap_session, char *error_msg,
  */
 void
 capture_input_cfilter_error_message(capture_session *cap_session, guint i,
-                                    char *error_message)
+                                    const char *error_message)
 {
     capture_options *capture_opts = cap_session->capture_opts;
     dfilter_t *rfcode = NULL;