diff --git a/blueprintcompiler/decompiler.py b/blueprintcompiler/decompiler.py
index a8b1c70..d8f505b 100644
--- a/blueprintcompiler/decompiler.py
+++ b/blueprintcompiler/decompiler.py
@@ -122,6 +122,13 @@ class DecompileCtx:
                 self._blocks_need_end[-1] = _CLOSING[line[-1]]
             self._indent += 1
 
+    def get_enum_value(self, value, type):
+        for member in type.members.values():
+            if member.nick == value or member.c_ident == value:
+                return member.name
+
+        return value.replace('-', '_')
+
 
     def print_attribute(self, name, value, type):
         if type is None:
@@ -142,15 +149,10 @@ class DecompileCtx:
         elif type.assignable_to(self.gir.namespaces["Gtk"].lookup_type("GObject.Object")):
             self.print(f"{name}: {value};")
         elif isinstance(type, Enumeration):
-            for member in type.members.values():
-                if member.nick == value or member.c_ident == value:
-                    self.print(f"{name}: {member.name};")
-                    break
-            else:
-                self.print(f"{name}: {value.replace('-', '_')};")
+            self.print(f"{name}: {self.get_enum_value(value, type)};")
         elif isinstance(type, Bitfield):
-            flags = re.sub(r"\s*\|\s*", " | ", value).replace("-", "_")
-            self.print(f"{name}: {flags};")
+            flags = [self.get_enum_value(flag, type) for flag in value.split("|")]
+            self.print(f"{name}: {' | '.join(flags)};")
         else:
             self.print(f"{name}: \"{escape_quote(value)}\";")
 
diff --git a/blueprintcompiler/language/values.py b/blueprintcompiler/language/values.py
index 29e5d98..5b49166 100644
--- a/blueprintcompiler/language/values.py
+++ b/blueprintcompiler/language/values.py
@@ -109,6 +109,13 @@ class LiteralValue(Value):
 class Flag(AstNode):
     grammar = UseIdent("value")
 
+    @property
+    def c_ident(self):
+        if isinstance(self.parent.parent.value_type, gir.Bitfield):
+            return self.parent.parent.value_type.members[self.tokens["value"]].c_ident
+        else:
+            return self.tokens["value"]
+
     @docs()
     def docs(self):
         type = self.parent.parent.value_type
@@ -137,15 +144,15 @@ class FlagsValue(Value):
             raise CompileError(f"{type.full_name} is not a bitfield type")
 
     def emit_xml(self, xml: XmlEmitter):
-        xml.put_text("|".join([flag.tokens["value"] for flag in self.children[Flag]]))
+        xml.put_text("|".join([flag.c_ident for flag in self.children[Flag]]))
 
 
 class IdentValue(Value):
     grammar = UseIdent("value")
 
     def emit_xml(self, xml: XmlEmitter):
-        if isinstance(self.parent.value_type, gir.Enumeration):
-            xml.put_text(self.parent.value_type.members[self.tokens["value"]].nick)
+        if isinstance(self.parent.value_type, gir.Enumeration) or isinstance(self.parent.value_type, gir.Bitfield):
+            xml.put_text(self.parent.value_type.members[self.tokens["value"]].c_ident)
         else:
             xml.put_text(self.tokens["value"])
 
diff --git a/tests/samples/accessibility.ui b/tests/samples/accessibility.ui
index 50e98c8..6f53b0b 100644
--- a/tests/samples/accessibility.ui
+++ b/tests/samples/accessibility.ui
@@ -5,7 +5,7 @@
     <accessibility>
       <property name="label" translatable="true">Hello, world!</property>
       <relation name="labelled-by">my_label</relation>
-      <state name="checked">true</state>
+      <state name="checked">GTK_ACCESSIBLE_TRISTATE_TRUE</state>
     </accessibility>
   </object>
   <object class="GtkLabel" id="my_label"></object>
diff --git a/tests/samples/enum.ui b/tests/samples/enum.ui
index acad161..b3d2a17 100644
--- a/tests/samples/enum.ui
+++ b/tests/samples/enum.ui
@@ -2,6 +2,6 @@
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkScrolledWindow">
-    <property name="window-placement">top-left</property>
+    <property name="window-placement">GTK_CORNER_TOP_LEFT</property>
   </object>
 </interface>
diff --git a/tests/samples/flags.blp b/tests/samples/flags.blp
index aafda40..453c123 100644
--- a/tests/samples/flags.blp
+++ b/tests/samples/flags.blp
@@ -6,5 +6,5 @@ Gio.Application {
 }
 
 EventControllerScroll {
-  flags: vertical;
+  flags: both_axes;
 }
diff --git a/tests/samples/flags.ui b/tests/samples/flags.ui
index d2bac55..244c68a 100644
--- a/tests/samples/flags.ui
+++ b/tests/samples/flags.ui
@@ -2,9 +2,9 @@
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GApplication">
-    <property name="flags">is_service|handles_open</property>
+    <property name="flags">G_APPLICATION_IS_SERVICE|G_APPLICATION_HANDLES_OPEN</property>
   </object>
   <object class="GtkEventControllerScroll">
-    <property name="flags">vertical</property>
+    <property name="flags">GTK_EVENT_CONTROLLER_SCROLL_BOTH_AXES</property>
   </object>
 </interface>
diff --git a/tests/samples/property.ui b/tests/samples/property.ui
index a2d5a1b..57cd9fc 100644
--- a/tests/samples/property.ui
+++ b/tests/samples/property.ui
@@ -2,6 +2,6 @@
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkBox">
-    <property name="orientation">vertical</property>
+    <property name="orientation">GTK_ORIENTATION_VERTICAL</property>
   </object>
 </interface>
diff --git a/tests/samples/size_group.ui b/tests/samples/size_group.ui
index 6d92edd..b518fd6 100644
--- a/tests/samples/size_group.ui
+++ b/tests/samples/size_group.ui
@@ -2,7 +2,7 @@
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkSizeGroup">
-    <property name="mode">horizontal</property>
+    <property name="mode">GTK_SIZE_GROUP_HORIZONTAL</property>
     <widgets>
       <widget name="label"/>
       <widget name="button"/>