diff --git a/libpostproc/postprocess.c b/libpostproc/postprocess.c
index e52574c397..9f5ab1fcbb 100644
--- a/libpostproc/postprocess.c
+++ b/libpostproc/postprocess.c
@@ -697,7 +697,7 @@ static inline void postProcess(uint8_t src[], int srcStride, uint8_t dst[], int
 
 /* -pp Command line Help
 */
-char *pp_help=
+const char *const pp_help=
 "Available postprocessing filters:\n"
 "Filters                        Options\n"
 "short  long name       short   long option     Description\n"
diff --git a/libpostproc/postprocess.h b/libpostproc/postprocess.h
index e3ac29e2e4..52211c5739 100644
--- a/libpostproc/postprocess.h
+++ b/libpostproc/postprocess.h
@@ -42,7 +42,7 @@
 typedef void pp_context_t;
 typedef void pp_mode_t;
 
-extern char *pp_help; ///< a simple help text
+extern const char *const pp_help; ///< a simple help text
 
 void  pp_postprocess(uint8_t * src[3], int srcStride[3],
                  uint8_t * dst[3], int dstStride[3],