diff --git a/src/Makefile b/src/Makefile
index dd631153..68256ab5 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -729,11 +729,11 @@ endif
 
 # GIT revision number
 version.c:	$(REVISION_CACHE)
-	echo "char SVN_revision[]=\"$(GIT_REVISION)\";" > version.c
+	echo "const char SVN_revision[]=\"$(GIT_REVISION)\";" > version.c
 
 ifneq ($(LABEL),)
 pversion.c:	$(LABEL_CACHE)
-	echo "char Program_version[]=\"$(LABEL)\";" > pversion.c
+	echo "const char Program_version[]=\"$(LABEL)\";" > pversion.c
 endif
 
 $(OBJDIR)/versiontag: pversion.c $(REVISION_CACHE)
diff --git a/src/help.c b/src/help.c
index 1726672a..7f1df9d9 100644
--- a/src/help.c
+++ b/src/help.c
@@ -62,8 +62,8 @@
 #include "pages.h"
 #include "factory.h"
 
-extern char Program_version[]; // generated in pversion.c
-extern char SVN_revision[]; // generated in version.c
+extern const char Program_version[]; // generated in pversion.c
+extern const char SVN_revision[]; // generated in version.c
 
 // Recherche un raccourci clavier:
 word * Shortcut(word shortcut_number)
diff --git a/src/pversion.c b/src/pversion.c
index 62c9cbed..5e896de5 100644
--- a/src/pversion.c
+++ b/src/pversion.c
@@ -1,2 +1,2 @@
-char Program_version[]="2.5";
+const char Program_version[]="2.5";