diff --git a/distrho/DistrhoDetails.hpp b/distrho/DistrhoDetails.hpp
index b1235209..65380859 100644
--- a/distrho/DistrhoDetails.hpp
+++ b/distrho/DistrhoDetails.hpp
@@ -236,18 +236,18 @@ enum PredefinedPortGroupsIds {
    /**
      Null or unset port group.
     */
-    kPortGroupNone = (uint32_t)-1,
+    kPortGroupNone = static_cast<uint32_t>(-1),
 
    /**
      A single channel audio group.
     */
-    kPortGroupMono = (uint32_t)-2,
+    kPortGroupMono = static_cast<uint32_t>(-2),
 
    /**
      A 2-channel discrete stereo audio group,
      where the 1st audio port is the left channel and the 2nd port is the right channel.
     */
-    kPortGroupStereo = (uint32_t)-3
+    kPortGroupStereo = static_cast<uint32_t>(-3)
 };
 
 /**