diff --git a/webapprt/gtk/webapprt.cpp b/webapprt/gtk/webapprt.cpp
index 08a293bf5452..69503c23daa1 100644
--- a/webapprt/gtk/webapprt.cpp
+++ b/webapprt/gtk/webapprt.cpp
@@ -384,8 +384,8 @@ int main(int argc, char *argv[])
   snprintf(appIniPath, MAXPATHLEN, "%s/%s", firefoxDir, kAPP_INI);
 
   if (NS_FAILED(parser.Init(appIniPath))) {
-    ErrorDialog("This app requires that Firefox version 16 or above is installed."
-                " Firefox 16+ has not been detected.");
+    ErrorDialog("This app requires a Firefox version between 16 and 47 to be installed."
+                " No compatible version of Firefox has been detected.");
     return 255;
   }
 
diff --git a/webapprt/mac/webapprt.mm b/webapprt/mac/webapprt.mm
index f2b6fc20d1fe..0d69bd0d3a14 100644
--- a/webapprt/mac/webapprt.mm
+++ b/webapprt/mac/webapprt.mm
@@ -381,7 +381,7 @@ NSString
   }
 
   NSLog(@"unable to find a valid webrt path");
-  @throw MakeException(@"This App requires that Firefox version 16 or above is installed.", @"Firefox 16+ has not been detected.");
+  @throw MakeException(@"This app requires a Firefox version between 16 and 47 to be installed.", @"No compatible version of Firefox has been detected.");
 
   return nil;
 }
diff --git a/webapprt/win/webapprt.cpp b/webapprt/win/webapprt.cpp
index 9c9e733a7e44..dd23f949ce25 100644
--- a/webapprt/win/webapprt.cpp
+++ b/webapprt/win/webapprt.cpp
@@ -524,7 +524,7 @@ main(int argc, char* argv[])
   }
 
   // We've done all we know how to do to try to find and launch FF
-  Output("This app requires that Firefox version 16 or above is installed."
-         " Firefox 16+ has not been detected.");
+  Output("This app requires a Firefox version between 16 and 47 to be installed."
+         " No compatible version of Firefox has been detected.");
   return 255;
 }