diff --git a/src/grovescam/grovescam.cxx b/src/grovescam/grovescam.cxx
index 6db79e92..222848ce 100644
--- a/src/grovescam/grovescam.cxx
+++ b/src/grovescam/grovescam.cxx
@@ -369,7 +369,7 @@ bool GROVESCAM::doCapture()
   return true;
 }
 
-bool GROVESCAM::storeImage(char *fname)
+bool GROVESCAM::storeImage(const char *fname)
 {
   if (!fname)
     {
diff --git a/src/grovescam/grovescam.h b/src/grovescam/grovescam.h
index da65e448..6d8680e8 100644
--- a/src/grovescam/grovescam.h
+++ b/src/grovescam/grovescam.h
@@ -169,7 +169,7 @@ namespace upm {
      * @param fname Name of the file to write
      * @return True if successful
      */
-    bool storeImage(char *fname);
+    bool storeImage(const char *fname);
 
     /**
      * Returns the picture length. Note: this is only valid after