diff --git a/mozilla/calendar/libical/src/libical/icalcomponent.c b/mozilla/calendar/libical/src/libical/icalcomponent.c
index b610fbac44a..6c7c373a0a1 100644
--- a/mozilla/calendar/libical/src/libical/icalcomponent.c
+++ b/mozilla/calendar/libical/src/libical/icalcomponent.c
@@ -48,7 +48,7 @@
 #include <limits.h> /* for INT_MAX */
 
 #ifdef WIN32
-#define snprintf        _snprintf
+#define strncasecmp      strnicmp
 #endif
 
 
diff --git a/mozilla/calendar/libical/src/libical/icalderivedparameter.c.in b/mozilla/calendar/libical/src/libical/icalderivedparameter.c.in
index da277966da4..c778fde077f 100644
--- a/mozilla/calendar/libical/src/libical/icalderivedparameter.c.in
+++ b/mozilla/calendar/libical/src/libical/icalderivedparameter.c.in
@@ -43,6 +43,10 @@
 #include <errno.h>
 #include <string.h> /* for memset() */
 
+#ifdef WIN32
+#define strcasecmp      stricmp
+#endif
+
 icalvalue_kind icalparameter_value_to_value_kind(icalparameter_value value);
 
 struct icalparameter_impl* icalparameter_new_impl(icalparameter_kind kind);
diff --git a/mozilla/calendar/libical/src/libical/icalrecur.c b/mozilla/calendar/libical/src/libical/icalrecur.c
index 13fa41b4e6e..20113be548b 100644
--- a/mozilla/calendar/libical/src/libical/icalrecur.c
+++ b/mozilla/calendar/libical/src/libical/icalrecur.c
@@ -146,6 +146,10 @@ typedef long intptr_t;
 #endif
 #endif
 
+#ifdef WIN32
+#define strcasecmp      stricmp
+#endif
+
 #include "icalrecur.h"
 
 #include "icalerror.h"