diff --git a/configure.ac~ b/configure.ac
index 05057e9..6ae550b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2954,13 +2954,26 @@ $ac_cv_sizeof_int)
   guint64_constant='(val)'
   ;;
 $ac_cv_sizeof_long)
-  gint64=long
-  gint64_modifier='"l"'
-  gint64_format='"li"'
-  guint64_format='"lu"'
-  glib_extension=
-  gint64_constant='(val##L)'
-  guint64_constant='(val##UL)'
+  case $host in
+  *-*-darwin*)
+    gint64='long long'
+    gint64_modifier='"ll"'
+    gint64_format='"lli"'
+    guint64_format='"llu"'
+    glib_extension=
+    gint64_constant='(val##LL)'
+    guint64_constant='(val##ULL)'
+    ;;
+  *)
+    gint64=long
+    gint64_modifier='"l"'
+    gint64_format='"li"'
+    guint64_format='"lu"'
+    glib_extension=
+    gint64_constant='(val##L)'
+    guint64_constant='(val##UL)'
+    ;;
+  esac
   ;;
 $ac_cv_sizeof_long_long)
   gint64='long long'
@@ -3053,12 +3066,23 @@ $ac_cv_sizeof_int)
   glib_gpui_cast='(guint)'
   ;;
 $ac_cv_sizeof_long)
-  glib_intptr_type_define=long
-  gintptr_modifier='"l"'
-  gintptr_format='"li"'
-  guintptr_format='"lu"'
-  glib_gpi_cast='(glong)'
-  glib_gpui_cast='(gulong)'
+  case $host in *-*-darwin*)
+    glib_intptr_type_define='long long'
+    gintptr_modifier='"I64"'
+    gintptr_format='"I64i"'
+    guintptr_format='"I64u"'
+    glib_gpi_cast='(gint64)'
+    glib_gpui_cast='(guint64)'
+    ;;
+  *)
+    glib_intptr_type_define=long
+    gintptr_modifier='"l"'
+    gintptr_format='"li"'
+    guintptr_format='"lu"'
+    glib_gpi_cast='(glong)'
+    glib_gpui_cast='(gulong)'
+    ;;
+  esac
   ;;
 $ac_cv_sizeof_long_long)
   glib_intptr_type_define='long long'
@@ -3193,7 +3217,14 @@ $ac_cv_sizeof_int)
   gint64=int
   ;;
 $ac_cv_sizeof_long)
-  gint64=long
+  case $host in
+  *-*-darwin*)
+    gint64='long long'
+    ;;
+  *)
+    gint64=long
+    ;;
+  esac
   ;;
 $ac_cv_sizeof_long_long)
   gint64='long long'