diff --git a/toolkit/components/remote/nsRemoteService.cpp b/toolkit/components/remote/nsRemoteService.cpp
--- a/toolkit/components/remote/nsRemoteService.cpp
+++ b/toolkit/components/remote/nsRemoteService.cpp
@@ -107,7 +107,8 @@
   bool useX11Remote = mozilla::widget::GdkIsX11Display();
 
 #  if defined(MOZ_ENABLE_DBUS)
-  if (!useX11Remote || getenv(DBUS_REMOTE_ENV)) {
+  const char* dbusRemoteEnv = getenv(DBUS_REMOTE_ENV);
+  if (!useX11Remote || (dbusRemoteEnv && *dbusRemoteEnv == '1')) {
     client = MakeUnique<nsDBusRemoteClient>();
   }
 #  endif
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -4125,7 +4125,7 @@
   const char* x11Display = PR_GetEnv("DISPLAY");
   // MOZ_ENABLE_WAYLAND is our primary Wayland on/off switch.
   const char* waylandPref = PR_GetEnv("MOZ_ENABLE_WAYLAND");
-  bool enableWayland = !x11Display || (waylandPref && *waylandPref);
+  bool enableWayland = !x11Display || (waylandPref && *waylandPref == '1');
   if (!enableWayland) {
     const char* backendPref = PR_GetEnv("GDK_BACKEND");
     enableWayland = (backendPref && strncmp(backendPref, "wayland", 7) == 0);
diff --git a/widget/gtk/nsFilePicker.cpp b/widget/gtk/nsFilePicker.cpp
--- a/widget/gtk/nsFilePicker.cpp
+++ b/widget/gtk/nsFilePicker.cpp
@@ -616,7 +616,7 @@
   if (mUseNativeFileChooser && sGtkNativeDialogShowPtr != nullptr) {
     const char* portalEnvString = g_getenv("GTK_USE_PORTAL");
     bool setPortalEnv =
-        (portalEnvString && atoi(portalEnvString) == 0) || !portalEnvString;
+        (portalEnvString && *portalEnvString == '0') || !portalEnvString;
     if (setPortalEnv) {
       setenv("GTK_USE_PORTAL", "1", true);
     }
diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -8835,7 +8835,7 @@
   // decorations does not work with CSD.
   // We check GTK_CSD as well as gtk_window_should_use_csd() does.
   const char* csdOverride = getenv("GTK_CSD");
-  if (csdOverride && atoi(csdOverride)) {
+  if (csdOverride && *csdOverride == '1') {
     sGtkWindowDecoration = GTK_DECORATION_CLIENT;
     return sGtkWindowDecoration;
   }