diff --git a/webapprt/Makefile.in b/webapprt/Makefile.in
index 64d18ad9aed..24c4f379124 100644
--- a/webapprt/Makefile.in
+++ b/webapprt/Makefile.in
@@ -48,7 +48,10 @@ libs:: prefs.js
 
 GRE_MILESTONE := $(shell tail -n 1 $(topsrcdir)/config/milestone.txt 2>/dev/null || tail -1 $(topsrcdir)/config/milestone.txt)
 GRE_BUILDID := $(shell cat $(DEPTH)/config/buildid)
-DEFINES += -DGRE_MILESTONE=$(GRE_MILESTONE) -DGRE_BUILDID=$(GRE_BUILDID)
+DEFINES += -DGRE_MILESTONE=$(GRE_MILESTONE) \
+           -DGRE_BUILDID=$(GRE_BUILDID) \
+           -DMOZ_APP_BASENAME=$(MOZ_APP_BASENAME) \
+           $(NULL)
 
 webapprt.ini: application.ini.in $(DEPTH)/config/buildid $(topsrcdir)/config/milestone.txt
 	$(PYTHON) $(topsrcdir)/config/Preprocessor.py $(DEFINES) $< > $@
diff --git a/webapprt/application.ini.in b/webapprt/application.ini.in
index 01b7c6815df..42ac2c1151a 100644
--- a/webapprt/application.ini.in
+++ b/webapprt/application.ini.in
@@ -12,6 +12,7 @@ Vendor=Mozilla
 Name=Webapp Runtime
 Version=@GRE_MILESTONE@
 BuildID=@GRE_BUILDID@
+UAName=@MOZ_APP_BASENAME@
 
 [Gecko]
 MinVersion=@GRE_MILESTONE@
diff --git a/webapprt/prefs.js b/webapprt/prefs.js
index bcd34ebf95b..e61a73b8888 100644
--- a/webapprt/prefs.js
+++ b/webapprt/prefs.js
@@ -4,4 +4,3 @@
 
 pref("browser.chromeURL", "chrome://webapprt/content/webapp.xul");
 pref("browser.download.folderList", 1);
-pref("general.useragent.compatMode.firefox", true);